CN107738658A - A kind of 100% low-floor tramcar vehicle body bottom frame - Google Patents

Abstract

The invention relates to a 100% low-floor tram car body chassis, which is assembled and welded by two parts, the front part of the chassis connected with the driver's cab and the chassis located above the wheel set area of the bogie. The rear part of the frame, the front part of the underframe includes the front end beam, the front side beams on both sides and the main beam, at least two front longitudinal beams are arranged between the front end beam and the main beam, and the rear part of the underframe includes the rear end beam, the rear side beam, It is composed of two rear longitudinal beams and two sets of bogie cover plates. The two ends of the rear longitudinal beams are respectively welded and fixed on the rear end beam and the main beam. The material of the front part of the chassis and the rear part of the chassis is stainless steel. The composition is made of bent stainless steel plate, and the hinged mount is welded on the rear end beam. The invention has the advantages of light weight, good strength and rigidity, and good force transmission performance. The rear part of the chassis in the bogie area adopts a modular design, which can realize structural interchange with the corresponding area of the intermediate car, and improves maintenance efficiency. Versatility.

Description

A 100% low-floor tramcar body underframe

technical field

The invention belongs to the technical field of rail transit, and in particular relates to a 100% low-floor tram car body underframe.

Background technique

100% low-floor tram is one of the important tools of modern urban rail transit. It is popular among cities for its convenience for passengers, diverse marshalling, flexible operation, and sharing of existing bus stops and road resources.

The underframe is one of the important parts of a 100% low-floor car body. For the car body underframe on the bogie, it bears the weight of the car body and needs to transmit the traction force from the bogie to the car body. Therefore, the car body is required Body chassis has a certain strength and rigidity, and requires better force transmission performance.

At present, the underframe of the low-floor car body is mainly designed with an all-carbon steel structure or an all-aluminum alloy profile structure. The all-carbon steel car body chassis has good strength and rigidity, but its weight is too large; the aluminum alloy profile car body chassis is light in weight, but its rigidity is low. In order to increase the bending stiffness and prevent the plate from being unstable, the plate must be enlarged. thick. In addition, aluminum alloy materials have poor corrosion resistance and need to be protected against corrosion.

Contents of the invention

The main purpose of the present invention is to solve the above problems and provide a 100% low-floor tram car body chassis with light weight, good strength and rigidity, good force transmission performance and high modularization degree.

For realizing the above object, technical scheme of the present invention is:

A 100% low-floor tram body underframe, said underframe is assembled and welded from two parts, the front part of the underframe connected to the driver's cab and the part above the wheel set area of the bogie The rear part of the underframe; the front part of the underframe includes a front end beam, front side beams on both sides and a main crossbeam, the two sides of the front end beam and the main crossbeam are welded and fixed on the front side beams on both sides, and the front end beam and the main crossbeam At least two front longitudinal beams are arranged between the main beams, and a plurality of small front beams are arranged between the front longitudinal beams and between the front longitudinal beams and the front edge beams; the rear part of the chassis includes rear end beams, It is composed of rear edge beams on both sides, two rear longitudinal beams and two sets of bogie cover plates. On the rear end beam and the main cross beam, the two sets of bogie cover plates are respectively welded and fixed on the corresponding side of the rear longitudinal beam, rear side beam and front side beam, between the rear longitudinal beams and between the rear longitudinal beam and the front side beam. A plurality of small rear beams are respectively arranged between the rear side beam and/or the front side beam; the material of the front part of the underframe and the rear part of the underframe is stainless steel, and the cover plate of the bogie is formed by bending stainless steel plates. The hinged mounting seat is welded on the rear end beam described above.

Further, two front longitudinal beams are arranged between the front end beam and the main cross beam, and the two front longitudinal beams are arranged obliquely in a horizontal plane with a wide front and a narrow rear.

Furthermore, the front end beam and/or the front longitudinal beam and/or the main beam and/or the front small beam and/or the rear small beam are stainless steel plate bending structures.

Further, the section of the rear longitudinal beam is "II" shape, which is formed by splicing and welding the upper plate, the lower plate and two side plates.

Furthermore, both ends of the upper plate and the lower plate are in the shape of a “eight” that expands outwards.

Further, the rear longitudinal beam is generally in the shape of an arc whose middle part is upwardly bent along the length direction of the vehicle body.

Further, a C-shaped opening is provided in the middle of the rear end beam, and the end of the hinged mount is embedded in the C-shaped opening and welded.

Further, the hinged mounting base is a split structure, which is composed of butt welding of the front mounting base and the rear mounting base. A plurality of side risers are welded between the front mounting base and the rear mounting base. Mounting holes are arranged on the seat.

Further, the front mounting seat is formed by butt-welding two upper and lower "T"-shaped structural members.

Further, the rear end beam is a mouth-shaped beam, which is formed by butt-welding of two U-shaped bending pieces, the upper and the lower.

Further, the bogie cover plate composition includes a cover plate longitudinal beam composition and a first cover plate and a second cover plate for installing seats, two of the first cover plates are arranged symmetrically along the length direction of the car body, and the The second cover plate is installed in the middle of the two first cover plates, and the cover plate longitudinal beam is fixedly connected with the side wall, and the side parts of the first cover plate and the second cover plate are welded and fixed on the cover plate longitudinal beam. superior.

Further, a network-shaped reinforcing beam is arranged on the upper surface of the second cover plate.

Further, the cover plate stringer is composed of a cover plate stringer, a cover plate lower stringer and a plurality of first vertical beams arranged between the cover plate stringer and the cover plate lower stringer, the The front and rear ends of the lower longitudinal beam of the cover plate are respectively welded and connected to the front side beam and the rear side beam through the second vertical beam.

Further, a transverse stop mounting seat is provided on one side of the rear longitudinal beam facing the longitudinal centerline of the vehicle body, a transverse shock absorber mounting seat is provided on the opposite side, and a traction rod is provided on the lower surface thereof mount.

Further, the hinged mount is made of carbon steel.

In summary, the underframe of a 100% low-floor tram car body provided by the present invention is made of high-strength stainless steel as a whole, and its structure is a thin plate bending part. , good strength and rigidity, and good force transmission performance. In addition, the rear part of the chassis in the bogie area adopts a modular design, which can realize structural interchange with the corresponding area of the intermediate car, which simplifies the production process and improves the versatility of maintenance.

Description of drawings

Fig. 1 is the structural representation of vehicle body underframe of the present invention;

Fig. 2 is the back structural diagram of Fig. 1;

Fig. 3 is a partial structural diagram of the rear end beam of the present invention;

Fig. 4 is a structural diagram of the rear end longitudinal beam of the present invention;

Fig. 5 is a structural view of the hinged mount of the present invention.

As shown in Figures 1 to 5, the front part of the underframe 1, the rear part of the underframe 2, the front beam 3, the front side beam 4, the main beam 5, the front longitudinal beam 6, the front small beam 7, the vertical plate 8, and the backing plate 9 , stiffener plate 10, connector 11, reinforcing plate 12, rear end beam 13, rear edge beam 14, rear longitudinal beam 15, upper plate 15a, lower plate 15b, side plate 15c, bogie cover plate composition 16, the first Rear small beam 17, second rear small beam 18, third rear small beam 19, fourth rear small beam 20, shock absorber mount 21, hinge mount 22, C-shaped opening 23, front mount 24, rear mount Seat 25, side vertical plate 26, mounting hole 27, opening 28, cover plate longitudinal beam composition 29, cover plate lower longitudinal beam 29a, first cover plate 30, upper cover plate 30a, first end plate 30b, second end plate 30c, side plate 30d, second cover plate 31, cover plate 31a, end plate 31b, side plate 31c, bottom plate 31d, first vertical beam 32, second vertical beam 33, the third vertical beam 34, reinforcing plate 35, Reinforcing beam 36, lateral stop mounting seat 37, lateral shock absorber mounting seat 38, traction rod mounting seat 39.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

As shown in Fig. 1 and Fig. 2, a kind of 100% low-floor tram car body chassis provided by the present invention, its front end is connected with the driver's cab chassis, and the rear end passes between the car body chassis of the adjacent compartment. hinged. The underframe is assembled and welded by two parts, the front part 1 of the underframe connected with the driver's cab and the rear part 2 of the underframe located above the wheel set area of the bogie. In order to reduce the total weight of the underframe on the premise of ensuring the overall structural strength and rigidity of the underframe and meet the requirements of lightweight vehicles, in this embodiment, the materials of the front part 1 of the underframe and the rear part 2 of the underframe are preferably stainless steel materials .

As shown in Figure 1 and Figure 1, the front part 1 of the underframe includes the front end beam 3, the front side beam 4 and the main beam 5 located on both sides of the vehicle body transverse direction (referring to the width direction of the vehicle body). The frame is connected by bolt fastening or welding. The front end beam 3 and the main beam 5 are arranged parallel to each other. There are at least two front longitudinal beams 6 arranged in the middle of the front longitudinal beam 6, and a plurality of front small beams 7 are arranged between adjacent front longitudinal beams 6 and between the front longitudinal beams 6 and the front side rails 4, so as to further increase the 1 overall structural strength and stiffness. The front part 1 of the underframe is a frame structure as a whole, and the front end beam 3, the front side beam 4, the main beam 5, and the front longitudinal beam 6 are symmetrically arranged around the center line of the vehicle body longitudinal (referring to the length direction of the vehicle body).

In this embodiment, under the premise of ensuring the overall structural strength and rigidity of the front part 1 of the chassis, in order to reduce the weight, only two front longitudinal beams 6 are arranged between the front end beam 3 and the main beam 5, and the front longitudinal beam 6 The front and rear ends are respectively welded and connected to the front end beam 3 and the main cross beam 5, and the two front longitudinal beams 6 preferably adopt an oblique layout structure that is wide at the front and narrow at the rear on the horizontal plane, that is, the two front longitudinal beams 6 and the front end beam 3 The width between the connection points is greater than the width between the connection points with the main beam 5. This structure can make the force transmission effect of the front end of the car body smoother and improve the force transmission without increasing the total weight of the front part 1 of the chassis. performance.

In this embodiment, the front side rail 4 adopts a stainless steel profile structure with a profile cavity in the middle and an inverted L-shaped section to improve the structural strength and rigidity of the front side rail 4 and reduce welding stress. The front end beam 3 , the main beam 5 , the front longitudinal beam 6 , and the front small beam 7 all preferably adopt a stainless steel plate bending structure. Wherein, the front end beam 3 is a U-shaped bending part open to the rear, and a plurality of vertical plates 8 are welded inside the U-shaped bending part. The surface is welded to enhance the structural strength and rigidity of the front end beam 3 . There is a widened part where the upper flange of the front end beam 3 is connected to the front side beams 4 on both sides, so as to increase the welding area between the front end beam 3 and the front side beams 4 and increase the connection strength. Here, a triangular piece can also be welded separately. A reinforcing plate (not shown in the figure) is used to increase the strength of the connection. A plurality of backing plates 9 are evenly installed on the front surface of the front end beam 3 , and the backing plates 9 are installed on the front end beam 3 by bolts. The main crossbeam 5 is the same as the front end beam 3, and is a U-shaped bending part opened to the front. The front longitudinal beam 6 is also a U-shaped bending part. The front longitudinal beam 6 is open to the front side beam 4 on the same side. . Between the two front longitudinal beams 6, between each front longitudinal beam 6 and the front edge beam 4 on the same side, two front small cross beams 7 are arranged, and the front small cross beams 7 are also bent parts, and its section can be U Shape, also can be Z-shape, weld connection between front small beam 7 and front side beam 6 and front side beam 4, can also be welded with L-shaped connector 11 at the junction of front small beam 7 and front side beam 6, To increase the connection strength between the front small beam 7 and the front longitudinal beam 6. A triangular reinforcing plate 12 is also welded at the joint between the main beam 5 and the front side beam 4 to increase the connection strength between the main beam 5 and the front side beam 4 . A plurality of lightening holes are arranged on the main beam 5 and the front small beam 7 to further reduce the weight of the chassis under the premise of ensuring the structural strength and rigidity.

As shown in FIGS. 1 and 2 , the rear part of the underframe 2 includes a rear end beam 13 , a rear side beam 14 located on both lateral sides of the car body, a rear longitudinal beam 15 and two sets of bogie cover plates 16 . Both sides of the rear end beam 13 are welded and fixed on the rear side beams 14 on both sides. In order to improve the force transmission performance of the underframe, in this embodiment, two rear longitudinal beams 15 are set in the rear part 2 of the underframe. The preceding two ends of the longitudinal beam 15 are respectively welded and fixed on the main beam 5 and the rear end beam 13 . The two sets of bogie cover plates 16 are respectively welded and fixed on the rear longitudinal beams 15, rear side beams 14 and front side beams 4 on the corresponding sides. flush. The rear end beam 13, two rear side beams 14, two rear longitudinal beams 15 and two groups of bogie cover plates 16 are arranged symmetrically around the center line of the longitudinal direction of the vehicle body (referring to the length direction of the vehicle body). The part of the rear part 2 of the chassis in the bogie area adopts a modular design, which can realize structural interchange with the corresponding area of the intermediate car, which simplifies the production process and improves the versatility of maintenance.

As shown in FIG. 2 , FIG. 3 and FIG. 4 , in this embodiment, two rear longitudinal beams 15 are arranged correspondingly to two front longitudinal beams 6 to ensure force transmission performance. The rear longitudinal beam 15 is generally in the shape of an upwardly curved middle part along the length direction of the car body, so as to meet the space requirement of the lower bogie. In order to improve the structural strength and force transmission performance of the rear longitudinal beam 15, the cross section of the rear longitudinal beam 15 is preferably "II" shape, which is spliced and welded by the upper plate 15a, the lower plate 15b and two side plates 15c. The ends of the upper plate 15a, the lower plate 15b and the two side plates 15c are respectively welded to the main crossbeam 5 and the rear end beam 13, and preferably, the upper plate 15a and the lower plate 15b are in the shape of a " The "eight"-shaped structure is used to increase the welding area between the rear longitudinal beam 15, the main beam 5 and the rear end beam 13, improve the connection strength of the rear longitudinal beam 15, and further improve the force transmission performance.

The rear side rail 14 has the same structure as the front side rail 4, both adopting a stainless steel profile structure with a profile cavity in the middle and an inverted L-shaped section to improve the structural strength and rigidity of the front side rail 4 and reduce welding stress.

Between the two rear longitudinal beams 15 and between the rear longitudinal beams 15, the rear side beams 14 and the front side beams 4, a plurality of small rear beams are arranged respectively to further increase the overall structural strength and rigidity of the rear part 2 of the chassis. A first rear small beam 17 is welded between the rear longitudinal beam 15 and the same side front side beam 4, and a second rear small beam 18 is also welded between the rear longitudinal beam 15 and the same side rear side beam 14. Four rear small crossbeams are welded between the two rear longitudinal beams 15, and the two sides of the third rear small crossbeam 19 positioned at the front end and the rear end are respectively welded on the side surfaces of the rear longitudinal beams 15 on both sides, and the two rear small crossbeams located in the middle The fourth rear small beam 20 is welded on the lower surface of the rear longitudinal beam 15 on both sides, and the shock absorber mounting seat 21 is welded on the fourth rear small beam 20, and the fourth rear small beam 20 is welded and fixed on the rear longitudinal beam 15 At the same time, the lower surface of the rear longitudinal beam 15 can also offset the height difference formed by the upward bending in the middle of the rear longitudinal beam 15, so that the floor between the two rear longitudinal beams 15 is even. The first rear small crossbeam 17, the second rear small crossbeam 18, and the third rear small crossbeam 19 all adopt a stainless steel bending structure, and the section is U-shaped or Z-shaped. The fourth rear small beam 20 is tailor-welded from two L-shaped stainless steel plates and a connecting plate in the middle, so as to further improve the structural strength and rigidity of the fourth rear small beam 20 . The connection between the fourth rear small beam 20 and the rear longitudinal beam 15 can also be welded with a reinforcing rib plate 10 to further increase the connection strength.

As shown in Figure 2 and Figure 3, in this embodiment, the rear end beam 13 is preferably a mouth-shaped beam, which is formed by butt welding of two U-shaped bending parts on the upper and lower sides, so as to improve the structural strength and transmission of the rear end beam 13. force performance, while increasing the connection strength with the hinged mount 22.

A C-shaped opening 23 is provided in the middle of the rear end beam 13, and the front end of the hinged mounting base 22 is embedded and connected in the C-shaped opening 23, and the C-shaped opening 23 is in contact with the edge of the hinged mounting base 22. Soldering makes the connection. The hinged mounting base 22 has a trapezoidal shape as a whole, and the width of the end connected to the C-shaped opening 23 is greater than that of the other end, so as to increase the welding area between the hinged mounting base 22 and the rear end beam 13 and increase the connection strength.

As shown in Figure 3 and Figure 5, in order to facilitate the assembly of the hinged mounting base 22, the hinged mounting base 22 adopts a split structure, which is formed by butt welding of the front mounting base 24 and the rear mounting base 25, and is installed on the front mounting base 24 and the rear mounting base. Two side vertical plates 26 are welded between the seats 25, and a mounting hole 27 for installing a hinge device is provided on the rear mounting seat 25. There is an opening 28 through up and down in the middle of the hinged mounting base 22 , which facilitates the installation of the hinged device while reducing weight.

The front mounting seat 24 is in the shape of an "I" after welding, and the frontmost horizontal and vertical edges of the "I" shape are welded to the edge circumference of the C-shaped opening 23 of the rear end beam 13. In order to facilitate the assembly of the hinged mounting base 22, the front mounting base 24 is formed by butt welding of two "T" shaped structural parts up and down, and the vertical section of the rear mounting base 25 is roughly U-shaped. The front mounting base 24 and the rear mounting base 25 Welding grooves are provided at the butt joint positions.

In this embodiment, the hinged mounting base 22 is made of carbon steel to improve the overall structural strength and rigidity of the hinged mounting base 22 . The two "T"-shaped structural members of the front mounting seat 24 and the rear mounting seat 25 are respectively cast from carbon steel to ensure strength and improve force transmission performance. The articulation mounting seat 22 is simple in process, has good rigidity and strength, and satisfies the load bearing requirements and installation space requirements.

The bogie cover plate assembly 16 is to provide a suitable working space for the bogie assembly and provide sufficient strength and rigidity for the seat installation on its upper part. As shown in Fig. 1 and Fig. 2, each set of bogie cover plates 16 has the same structure, including a cover plate stringer assembly 29 and a first cover plate 30 and a second cover plate 31 for installing seats. The first cover plate 30 is provided with two symmetrically along the length direction of the car body, and the transverse seat is installed on the first cover plate 30, and the second cover plate 31 is installed in the middle of the two first cover plates 30, and the second cover plate 31 is higher than The first cover plate 30 is installed, and the longitudinal seat is installed on the second cover plate 31 . The cover plate longitudinal beam composition 29 is used to connect the underframe and the side wall of the vehicle body, and the side parts of the first cover plate 30 and the second cover plate 31 are welded and fixed on the cover plate longitudinal beam composition 29 .

Cover plate stringer composition 29 is made up of cover plate stringer (not shown in the figure) and cover plate lower stringer 29a, and cover plate stringer and cover plate lower stringer 29a are arranged in parallel, and cover plate stringer and cover plate lower stringer 29a are arranged in parallel. A plurality of first upright beams 32 are arranged between the lower side beams 29a of the cover plate, and the front and rear ends of the lower side beams 29a of the cover plate are respectively welded to the front side beam 4 and the rear side beam 14 through the second upright beams 33 .

The longitudinal beam on the cover plate and the lower longitudinal beam 29a on the cover plate are formed by bending stainless steel plates. The section of the first vertical beam 32 is U-shaped. While reducing the weight, the structural strength and rigidity of the panel stringer composition 29 can be increased.

The first cover plate 30 is made up of upper cover plate 30a, first end plate 30b, second end plate 30c, side plate 30d, upper cover plate 30a, first end plate 30b, second end plate 30c, side plate 30d are made of stainless steel The plate is bent and formed, and the upper cover plate 30a is in the shape of steps as a whole, so as to cooperate with the installation of various parts of the bogie below. The bottom of the side plate 30d is welded and fixed on the upper plate 15a of the rear longitudinal beam 15, and the front and rear ends of the side plate 30d are respectively welded with a third vertical beam 34, and the bottom of the third vertical beam 34 is also welded on the top of the rear longitudinal beam 15. plate 15a. The other side of the first end plate 30b is welded to the second upright beam 33, and the side of the upper cover plate 30a is welded to the lower longitudinal beam 29a of the cover plate to meet the load-bearing requirements of the seat.

The second cover plate 31 is made up of cover plate 31a, front and rear end plates 31b, side plates 31c and bottom plate 31d, cover plate 31a, front and rear end plates 31b, side plates 31c, and bottom plate 31d are formed by bending stainless steel plates . The bottoms of the front and rear end plates 31b are welded to the upper cover plate 30a of the first cover plate 30, one side of the front and rear end plates 31b is welded to the first vertical beam 32, and the front and rear end plates 31b A reinforcing plate 35 is also welded between the other side and the upper cover plate 30a. One side of the cover plate 31a is welded to the first vertical beam 32 and the longitudinal beam on the cover plate. The side plate 31c is T-shaped and welded to the upper cover plate 30a and the second end plate 30c. The bottom plate 31d is welded to the second end plate 30c and the rear longitudinal beam 15, and the bottom plate 31d is flush with the aisle floor. On the upper surface of the cover plate 31a, there is also a network-shaped reinforcing beam 36 composed of cross beams and longitudinal beams, which increases the vertical stiffness of the second cover plate 31 and meets the load-bearing requirements of the seat.

On one side of the rear longitudinal beam 15 facing the longitudinal centerline of the vehicle body, a transverse stop mounting seat 37 is provided, a transverse shock absorber mounting seat 38 is provided on the opposite side, and a traction rod mounting seat is provided on its lower surface. 39.

The underframe structure of the present invention adopts high-strength stainless steel material as a whole, and the structure is a thin plate bending part, which not only has light weight, but also has good strength, rigidity and force transmission performance. The underframe structure can ensure that the height of all floors in the car body area is not higher than 350mm, and the trafficability is strong.

As mentioned above, a similar technical solution can be derived in combination with the content of the solution given in the accompanying drawings. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are still within the scope of the technical solutions of the present invention.

Claims (15)

1. A kind of 1. 100% low-floor tramcar vehicle body bottom frame, it is characterised in that：The chassis is organized weldering by two parts and formed, Two parts are respectively the chassis front portion and the chassis rear portion positioned at steering framing wheel to overlying regions being connected with drivers' cab；

   The chassis is anterior to include front beam, the front side beam and main beam of both sides, the both sides welding of the front beam and main beam It is fixed on the front side beam of both sides, at least two front longitudinals is provided between the front beam and main beam, described preceding vertical Multiple preceding needle beams are provided between beam and between front longitudinal and front side beam；

   The chassis rear portion includes back end beam, the rear side bar of both sides, two floor side members and two groups of bogie cover plate compositions, after described The both sides of end carriage are weldingly fixed on the rear side bar of both sides, and the both ends of the floor side member, which are respectively welded, is fixed on back end beam and main horizontal stroke Liang Shang, bogie cover plate composition is respectively welded on the floor side member for being fixed on respective side, rear side bar and front side beam described in two groups, Multiple rear needle beams are set respectively between longeron and between floor side member and rear side bar and/or front side beam in the rear；

   The chassis is anterior and the material at chassis rear portion be stainless steel, the bogie cover plate form by stainless steel plate bending and Into welding is hinged mounting seat on end carriage in the rear.
2. A kind of 2. 100% low-floor tramcar vehicle body bottom frame according to claim 1, it is characterised in that：Before described Two front longitudinals are set between end carriage and main beam, and two front longitudinals are in front wide and rear narrow oblique layout knot in the horizontal plane Structure.
3. A kind of 3. 100% low-floor tramcar vehicle body bottom frame according to claim 1, it is characterised in that：The front end Beam and/or front longitudinal and/or main beam and/or preceding needle beam and/or rear needle beam are stainless steel plate bending structure.
4. A kind of 4. 100% low-floor tramcar vehicle body bottom frame according to claim 1, it is characterised in that：It is vertical after described The section of beam is " II " shape, is welded by upper plate, lower plate and two side plate splicings.
5. A kind of 5. 100% low-floor tramcar vehicle body bottom frame according to claim 4, it is characterised in that：The upper plate At both ends it is in the "eight" shape extended out with lower plate.
6. A kind of 6. 100% low-floor tramcar vehicle body bottom frame according to claim 1, it is characterised in that：It is vertical after described The arc that beam is integrally bent upwards along length over ends of body direction in center section.
7. A kind of 7. 100% low-floor tramcar vehicle body bottom frame according to claim 1, it is characterised in that：The rear end The centre of beam is provided with c-shaped opening, and the end insertion of the be hinged mounting seat, which is arranged in the c-shaped opening, to be welded to connect.
8. A kind of 8. 100% low-floor tramcar vehicle body bottom frame according to claim 7, it is characterised in that：It is described be hinged Mounting seat is the structure of split, is made up of preceding mounting seat and rear mounting seat butt welding, in the preceding mounting seat and rear mounting seat Between be welded with multiple cant boards, mounting hole is provided with mounting seat in the rear.
9. A kind of 9. 100% low-floor tramcar vehicle body bottom frame according to claim 8, it is characterised in that：Pacify before described Dress seat is formed by upper and lower two " T " shape structures part butt welding.
10. A kind of 10. 100% low-floor tramcar vehicle body bottom frame according to claim 1, it is characterised in that：The rear end Beam is degree of lip-rounding beam, is formed by upper and lower two U-shapeds bending part butt welding.
11. A kind of 11. 100% low-floor tramcar vehicle body bottom frame according to claim 1, it is characterised in that：The steering Frame cover plate composition includes cover plate longeron and formed and for installing the first cover plate and the second cover plate of seat, and first cover plate is along car Body length direction is symmetrical arranged two, and second cover plate is arranged on the centre of two the first cover plates, the cover plate longeron composition It is fixedly connected with side wall, first cover plate, the sidepiece of the second cover plate are weldingly fixed on cover plate longeron composition.
12. A kind of 12. 100% low-floor tramcar vehicle body bottom frame according to claim 11, it is characterised in that：Described It is provided with the upper surface of second cover plate in netted panting beam.
13. A kind of 13. 100% low-floor tramcar vehicle body bottom frame according to claim 11, it is characterised in that：The lid Plate longeron composition is by longeron under longeron, cover plate on cover plate and is arranged on the cover plate multiple between longeron under longeron and cover plate First vertical beam is formed, and the rear and front end of longeron is connected by the second vertical beam and front side beam and rear side bar welding respectively under the cover plate Connect.
14. A kind of 14. 100% low-floor tramcar vehicle body bottom frame according to claim 1, it is characterised in that：In the rear The side towards car body longitudinal centre line of longeron is provided with horizontal backstop mounting seat, is provided with relative opposite side and laterally subtracts Shake device mounting seat, be provided with drawing pull bar mounting seat on the lower surface thereof.
15. A kind of 15. 100% low-floor tramcar vehicle body bottom frame according to claim 1, it is characterised in that：It is described be hinged Mounting seat is made up of carbon steel material.