阅读说明：本技术 一种摩托车的车架 (Frame of motorcycle ) 是由 汪中午 高思榜 陈增松 吴兵勇 于 2020-08-25 设计创作，主要内容包括：本发明提供了一种摩托车的车架,属于摩托车技术领域。它解决了现有摩托车车架上部件难以便捷地进行装配的技术问题。本摩托车的车架包括前部框架和后部框架,所述前部框架的后端固连有沿左右方向延伸的横梁管,所述后部框架包括固连于所述横梁管的横向中部且向后延伸的纵梁,所述横管梁的下方连接有连接支架,所述连接支架的横向中部固设有一个朝后上方延伸的支撑管,所述支撑管的上端与所述纵梁固连,所述支撑管、纵梁和连接支架之间形成用于容置安装部件的安装舱。本摩托车的车架能在保证强度的条件下使周边部件的安装布置更加便捷。(The invention provides a frame of a motorcycle, and belongs to the technical field of motorcycles. It has solved the technical problem that the part is difficult to assemble conveniently on the current motorcycle frame. The motorcycle frame comprises a front frame and a rear frame, wherein a cross beam pipe extending in the left-right direction is fixedly connected to the rear end of the front frame, the rear frame comprises a longitudinal beam fixedly connected to the transverse middle of the cross beam pipe and extending backwards, a connecting support is connected to the lower portion of the cross beam pipe, a supporting pipe extending towards the upper rear portion is fixedly arranged at the transverse middle of the connecting support, the upper end of the supporting pipe is fixedly connected with the longitudinal beam, and an installation cabin used for containing installation components is formed among the supporting pipe, the longitudinal beam and the connecting support. This frame of motorcycle can make the installation of peripheral parts arrange more convenient under the condition of assurance intensity.)

1. The frame of the motorcycle comprises a front frame (1) and a rear frame (2), wherein a cross beam pipe (3) extending in the left-right direction is fixedly connected to the rear end of the front frame (1), the frame is characterized in that the rear frame (2) comprises a longitudinal beam (21) fixedly connected to the transverse middle of the cross beam pipe (3) and extending backwards, a connecting support (4) is connected to the lower portion of the cross beam, a supporting pipe (5) extending towards the upper rear portion is fixedly arranged at the transverse middle of the connecting support (4), the upper end of the supporting pipe (5) is fixedly connected with the longitudinal beam (21), and an installation cabin (6) used for containing installation components is formed among the supporting pipe (5), the longitudinal beam (21) and the connecting support (4).

2. The frame of a motorcycle according to claim 1, characterized in that a downwardly extending pipe column (7) is fixedly connected to the bottom of the beam tube (3), a second horizontal pipe (8) extending in the left-right direction is fixedly connected to the lower end of the pipe column (7), and the upper end of the connecting bracket (4) is fixedly connected to the second horizontal pipe (8).

3. A frame for a motorcycle according to claim 1, wherein the dimension of the connecting bracket (4) in the left-right direction is gradually increased from bottom to top, and left and right sides of the connecting bracket (4) are arc-surface shaped.

4. The motorcycle frame according to claim 1, 2 or 3, wherein the connecting bracket (4) comprises a first enclosing plate (41) and a second enclosing plate (42) which are enclosed from left to right, through holes (43) which penetrate through and are opposite to each other in the left-right direction are respectively formed in the first enclosing plate (41) and the second enclosing plate (42), the lower end of the supporting tube (5) is located between the first enclosing plate (41) and the second enclosing plate (42), a mounting shaft (9) which extends in the left-right direction is fixedly connected to the lower end of the supporting tube (5), and two ends of the mounting shaft (9) are respectively inserted into the corresponding through holes (43) and are fixedly connected with the inner edges of the through holes (43).

5. A frame for a motorcycle according to claim 4, wherein the connecting bracket (4) is provided with a abdicating adjusting hole (44), the caliber size of the abdicating adjusting hole (44) is larger than the radial size of the supporting tube (5), and the supporting tube (5) penetrates through the abdicating adjusting hole (44).

6. The frame of the motorcycle according to claim 1, 2 or 3, wherein the rear end of the longitudinal beam (21) is provided with a turned-up section (211) which is formed by bending upwards relative to the body of the longitudinal beam (21), and the upper end surface of the supporting tube (5) is fixedly attached to the lower surface of the turned-up section (211).

7. A frame for a motorcycle according to claim 1, 2 or 3, wherein a reinforcing plate (10) is fixedly attached to the side member (21), the reinforcing plate (10) is U-shaped, left and right inner walls of the reinforcing plate (10) are fixedly attached to left and right sides of the side member (21), respectively, and a bottom inner wall of the reinforcing plate (10) is fixedly attached to an outer peripheral surface of an upper end of the support pipe (5).

8. The motorcycle frame of claim 7, characterized in that the left and right sides of the rear end of the longitudinal beam (21) are respectively fixedly connected with a first tailstock (11) and a second tailstock (12), the first tailstock (11) and the second tailstock (12) are arranged in bilateral symmetry, the left and right inner walls of the reinforcing plate (10) are respectively fixedly connected with the outer side surface of the first tailstock (11) and the outer side surface of the second tailstock (12), and the bottom inner wall of the reinforcing plate (10) is fixedly connected with the bottom surface of the first tailstock (11) and the bottom surface of the second tailstock (12).

9. A frame for a motorcycle according to claim 2, wherein one end of said cross member tube (3) has a mounting groove (31) for mounting a center suspension, said pipe column (7) has two pieces and is fixedly connected to the left and right ends of said second cross tube (8), the upper end of said pipe column (7) near said mounting groove (31) is located in front of said mounting groove (31) and is fixedly connected to the outer peripheral surface of said cross member tube (3), and the other said pipe column (7) extends in the radial direction of said cross member tube (3) and is offset from said pipe column (7) near said mounting groove (31) in the front-rear direction.

10. A frame for a motorcycle according to claim 1, 2 or 3, wherein said longitudinal beams (21) are square tubular members and said support tubes (5) are round tubular members.

Technical Field

The invention belongs to the technical field of motorcycles, and relates to a frame of a motorcycle.

Background

If the engine is said to be the "heart" of a motorcycle, then the frame is the "skeleton" of the motorcycle. The frame is closely related to the control performance and riding comfort of the motorcycle. The frame supports the engine, provides a fixed location for the steering mechanism and rear shock absorbers, carries the rider, passengers and their luggage, provides mounting locations for fuel tanks, batteries, etc., and so on.

A frame of a general motorcycle includes a front frame and a rear frame, and an engine, a transmission, and the like are mounted below the front frame. Vehicle equipment such as an ABS unit, a GPS unit, and a canister for recovering evaporated fuel can be added to the rear frame, but the width of the motorcycle in the left-right direction is too large due to the numerous peripheral components, and the assembly is not easy.

In order to solve the above problem, patent application publication No. CN102556243A discloses a motorcycle frame including a frame front portion extending rearward from a head pipe (2) and a frame rear portion extending downward from a rear end of the frame front portion to a rear side, wherein the frame front portion is formed of at least right and left paired frame members. On the other hand, the front side portion of the frame rear portion is a waist frame (5) having a closed cross-section structure in which a pair of left and right steel plates (50, 51) are overlapped with each other, and vehicle equipment such as a canister (7) and an ABS unit (9) can be easily mounted on the side surface of the narrow waist frame (5) while sufficient rigidity is ensured.

The frame structure can ensure that the vehicle body has a narrow width after being assembled to a certain degree, but is difficult to assemble conveniently when more peripheral components need to be installed. In order to further improve the convenience of assembling the peripheral components while ensuring the structural strength, it is necessary to consider a design that reduces the structural strength, and it is easy to consider such as: 1. the overall size and the section size of the frame are designed to be larger, so that the strength is ensured, and the capacity of parts is improved; 2. the perimeter component design is fitted to the aft perimeter of either the forward frame or the aft frame, spreading out the component density.

Disclosure of Invention

The invention provides a frame of a motorcycle aiming at the problems in the prior art, and the technical problems to be solved by the invention are as follows: how to facilitate the mounting arrangement of the peripheral components under the condition of ensuring the strength.

The purpose of the invention can be realized by the following technical scheme:

the frame of the motorcycle comprises a front frame and a rear frame, wherein a cross beam pipe extending in the left-right direction is fixedly connected to the rear end of the front frame, the rear frame is characterized in that the rear frame comprises a longitudinal beam fixedly connected to the transverse middle of the cross beam pipe and extending backwards, a connecting support is connected to the lower portion of the cross beam pipe, a supporting pipe extending towards the upper rear portion is fixedly arranged at the transverse middle of the connecting support, the upper end of the supporting pipe is fixedly connected with the longitudinal beam, and an installation cabin used for containing installation components is formed among the supporting pipe, the longitudinal beam and the connecting support.

The front frame of the motorcycle is used for assembling components such as an oil tank, an engine and the like, the rear frame is used for assembling components such as a seat cushion, a carbon tank, an ABS unit and the like, and the front frame and the rear frame are fixedly connected through a cross beam pipe, so that the integral stability of the whole frame structure is ensured. The rear frame comprises the longitudinal beam fixedly connected to the axial middle part of the cross beam tube and extending backwards, so that the longitudinal beam and the supporting tube are positioned in the middle of the frame in the width direction, the load borne by the longitudinal beam can be ensured to be more directly acted on the frame structure body, in addition, the transition between the front frame and the rear frame is smoother, the participation of the front frame in load sharing is facilitated, the integral load capacity of the rear frame is improved, and meanwhile, the longitudinal beam is directly and fixedly connected with the transverse cross beam, the design improvement of the installation height of the seat cushion is facilitated under the condition that the size of the frame is not changed, and the assembly; the connecting support capable of being connected with the transverse cross pipe beam is arranged below the transverse cross pipe beam, the supporting pipe which extends towards the upper rear side and is fixedly connected with the longitudinal beam is arranged on the connecting support, the supporting pipe and the longitudinal beam are vertically opposite, the supporting pipe and the connecting support form an installation cabin for accommodating installation components, and therefore an interference-free assembly area can be formed on the left side and the right side of the supporting pipe, the longitudinal beam and the connecting support, components such as a carbon tank or an ABS unit cannot be interfered by a rear frame when being installed, the assembly is more convenient, the installation cabin can further utilize the space between the supporting pipe, the longitudinal beam and the connecting support and has a protection effect, the assembly is suitable for assembling components which need to be protected and have long service life, and the peripheral component arrangement of the rear frame is more convenient.

In the frame of the motorcycle, the bottom of the beam pipe is fixedly connected with a pipe column extending downwards, the lower end of the pipe column is fixedly connected with a second transverse pipe extending along the left-right direction, and the upper end of the connecting support is fixedly connected with the second transverse pipe. Through linking firmly the tubular column in the bottom of crossbeam pipe, the second that makes the lower extreme of tubular column link firmly left right direction extension is violently managed, let linking bridge's upper end and second violently manage and link firmly, crossbeam pipe and second are violently managed the width size that only increases rear portion frame front end like this, can effectively improve the regional structural strength of linking bridge like this, and then guarantee the structural strength of stay tube and longeron, and crossbeam pipe and second are violently managed and can carry out better protection with the installation cavity just right region to the part of this department installation, in addition because crossbeam pipe and second are violently managed the edge that all is in the assembly region and can not cause obvious interference to the assembly of part, therefore can further improve the installation convenience of peripheral part under the condition of assurance intensity.

In the motorcycle frame, the dimension of the connecting bracket in the left-right direction gradually increases from bottom to top, and the left side and the right side of the connecting bracket are arc-surface-shaped. The size of the connecting support along the left and right directions is gradually increased from bottom to top, and the left and right sides of the connecting support are arc-surface-shaped, so that the conduction stability of the load when the load passes through the connecting support can be ensured, the phenomenon that the structure is unstable due to stress concentration is avoided, and in addition, the size of the lower end of the connecting support is smaller, and the arrangement of parts is more facilitated.

In the frame of the motorcycle, the connecting support comprises a first enclosing plate and a second enclosing plate which are enclosed from the left and the right, through holes which are penetrated and are opposite to each other along the left and the right directions are respectively arranged on the first enclosing plate and the second enclosing plate, the lower end of the supporting tube is positioned between the first enclosing plate and the second enclosing plate, the lower end of the supporting tube is fixedly connected with an installation shaft which extends along the left and the right directions, and two ends of the installation shaft are respectively inserted into the corresponding through holes and are fixedly connected with the inner edges of the through holes. Through setting up the linking bridge including the bounding wall one and the bounding wall two of controlling the inclusion, do benefit to like this and reduce whole weight when guaranteeing enough support intensity, through setting up the through-hole at bounding wall one and bounding wall two, and make the installation axle that the left and right directions of the lower extreme of stay tube linked firmly extend insert locate in the through-hole and link firmly with the inner edge of through-hole, can make the stay tube pass through installation axle and bounding wall one and bounding wall two normal running fit earlier like this in process of production, the pendulum position of fine setting stay tube makes it reach reasonable connection angle most with the longeron, so as to ensure to make peripheral part can have sufficient installation size between stay tube and longeron, at last will install the axle and the inner edge welding of through-hole again and link firmly, can further improve the convenience of.

In the motorcycle frame, the connecting bracket is provided with a yielding adjusting hole, the caliber size of the yielding adjusting hole is larger than the radial size of the supporting tube, and the supporting tube penetrates through the yielding adjusting hole. Through set up on linking bridge and let a position transfer hole, can guarantee like this that the stay tube can smoothly swing in order to look for the most reasonable fixed position before linking firmly with linking bridge.

In the frame of the motorcycle, the rear end of the longitudinal beam is provided with a tilting section which is formed by bending upwards relative to the body of the longitudinal beam, and the upper end surface of the supporting tube is attached and fixedly connected with the lower surface of the tilting section. The tilting section is arranged at the rear end of the longitudinal beam, so that the extending direction of the tilting section is closer to that of the supporting tube, the welding area of the supporting tube and the longitudinal beam is favorably increased, and the connecting strength between the supporting tube and the longitudinal beam is ensured.

In the frame of the motorcycle, the longitudinal beam is fixedly connected with the reinforcing plate, the reinforcing plate is U-shaped, the left inner wall and the right inner wall of the reinforcing plate are fixedly connected with the left side and the right side of the longitudinal beam respectively, and the bottom inner wall of the reinforcing plate is fixedly connected with the outer peripheral surface of the upper end of the supporting tube. The U-shaped reinforcing plates are fixedly connected with the left side and the right side of the longitudinal beam and the outer peripheral surface of the upper end of the supporting tube, so that the connecting effect of the supporting tube and the longitudinal beam is further improved, and the structural strength is ensured.

In the frame of the motorcycle, the left side and the right side of the rear end of the longitudinal beam are fixedly connected with the first tail frame and the second tail frame respectively, the first tail frame and the second tail frame are arranged in a bilateral symmetry mode, the left inner wall and the right inner wall of the reinforcing plate are fixedly connected with the outer side surface of the first tail frame and the outer side surface of the second tail frame respectively, and the bottom inner wall of the reinforcing plate is fixedly connected with the bottom surface of the first tail frame and the bottom surface of the second tail frame. Through linking firmly tailstock one and tailstock two respectively in the left and right sides of longeron rear end, tailstock one and tailstock two bilateral symmetry can provide more stable support to the longeron with front frame cooperation front rear both ends, inner wall still links firmly with the lateral surface of tailstock one and the lateral surface of tailstock two respectively about through setting up the reinforcing plate, the bottom inner wall of reinforcing plate still links firmly with the bottom surface of tailstock one and the bottom surface of tailstock two, the reinforcing plate can tie the upper end of stay tube between the bottom surface of reinforcing plate and longeron more steadily through the joint action of a plurality of dimensions like this, further improve structural stability.

In the frame of the motorcycle, one end of the cross beam pipe is provided with a mounting groove for mounting the middle suspension, the two pipe columns are fixedly connected to the left end and the right end of the second cross pipe respectively, the upper end of the pipe column close to the mounting groove is positioned in front of the mounting groove and fixedly connected with the outer peripheral surface of the cross beam pipe, and the other pipe column extends along the radial direction of the cross beam pipe and is arranged in a staggered manner with the pipe column close to the mounting groove along the front-back direction. Violently having linked firmly two tubular columns between pipe and the crossbeam pipe through setting up the second, the tubular column upper end that makes and is close to the mounting groove is located this mounting groove the place ahead and links firmly with the outer peripheral face of crossbeam pipe, another tubular column radially extends towards the crossbeam pipe and with the tubular column that is close to the mounting groove along fore-and-aft direction dislocation arrangement, mounting groove department can receive the supporting role that the middle part hung like this, the tubular column that is close to the mounting groove keeps relatively stable with the skew atress that makes the frame both sides of crossbeam pipe under the condition that the installation of guaranteeing that the middle part hangs does not receive the interference, further improve atress stability and assembly convenience.

In the frame of the motorcycle, the longitudinal beam is a square pipe member, and the support pipe is a round pipe member. The longitudinal beam is arranged to be a square pipe fitting, so that the welding effect of the longitudinal beam and the peripheral frame can be guaranteed to be more stable, and the supporting pipe is arranged to be a round pipe fitting, so that the vertical stress supporting effect of the round pipe fitting can be guaranteed to be better, and the round pipe fitting is not easy to bend and deform.

Compared with the prior art, the invention has the following advantages:

the motorcycle frame comprises a longitudinal beam which is fixedly connected with the axial middle part of a cross beam pipe and extends backwards through arranging a rear frame, a connecting bracket which can be connected with the cross beam pipe is arranged below the cross beam pipe, a supporting pipe which extends towards the back upper part and is fixedly connected with the longitudinal beam is arranged on the connecting bracket, the supporting pipe and the longitudinal beam are vertically opposite to each other, so that an installation cabin for accommodating installation components is formed among the supporting pipe, the longitudinal beam and the connecting bracket, thus, the left side and the right side of the supporting tube, the longitudinal beam and the connecting bracket can form an assembly area without interference, components such as the carbon tank or the ABS unit and the like can not be interfered by the rear frame when being installed, the assembly is more convenient, the installation cabin can further utilize the space among the supporting pipes, the longitudinal beams and the connecting supports, has a protection effect, is suitable for assembling parts which need to be protected and have long service life, and is more convenient for the arrangement of the parts on the periphery of the rear frame.

Drawings

Fig. 1 is a perspective view of a frame of the motorcycle.

Fig. 2 is a front view schematically showing the structure of the motorcycle frame.

Fig. 3 is a schematic top view of the motorcycle frame.

In the figure, 1, a front frame;

2. a rear frame; 21. a stringer; 211. a tilting section;

3. a beam tube; 31. mounting grooves;

4. connecting a bracket; 41. a first enclosing plate; 42. a second coaming; 43. a through hole; 44. a abdication adjusting hole;

5. supporting a tube; 6. installing a cabin; 7. a pipe string; 8. a second cross tube; 9. installing a shaft; 10. a reinforcing plate; 11. a first tailstock; 12. and a second tailstock.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1-3, the motorcycle frame comprises a front frame 1 and a rear frame 2, a cross beam pipe 3 extending in the left-right direction is fixedly connected to the rear end of the front frame 1, the rear frame 2 comprises a longitudinal beam 21 fixedly connected to the transverse middle of the cross beam pipe 3 and extending backwards, a connecting support 4 is connected to the lower portion of the cross beam pipe 3, a supporting pipe 5 extending towards the upper rear portion is fixedly arranged at the transverse trunk portion of the connecting support 4, the upper end of the supporting pipe 5 is fixedly connected with the longitudinal beam 21, the vertical projection of the longitudinal beam 21 coincides with the vertical projection of the supporting pipe 5, and an installation cabin 6 for accommodating installation components is formed among the supporting pipe 5, the longitudinal beam 21 and the connecting support 4. The front frame 1 of the motorcycle is used for assembling components such as an oil tank and an engine, the rear frame 2 is used for assembling components such as a seat cushion, a carbon tank and an ABS unit, and the front frame 1 and the rear frame 2 are fixedly connected through a cross beam pipe 3, so that the integral stability of the whole frame is ensured. The longitudinal beam 21 is a square pipe, and the support pipe 5 is a round pipe. Set up longeron 21 and can guarantee more stable with the welding effect of peripheral frame for square pipe fitting, set up stay tube 5 and can guarantee that its vertical atress supporting effect is better and difficult buckling deformation for pipe fitting. The rear frame 2 comprises the longitudinal beam 21 which is fixedly connected with the axial middle part of the cross beam pipe 3 and extends backwards, so that the longitudinal beam 21 and the supporting pipe 5 are positioned in the middle of the frame in the width direction, the load born by the longitudinal beam can be ensured to be more directly acted on the frame structure body, in addition, the transition between the front frame 1 and the rear frame 2 is smoother, the participation of the front frame 1 in load sharing is facilitated, the integral load capacity of the rear frame 2 is improved, and meanwhile, the longitudinal beam 21 is directly and fixedly connected with the cross beam pipe 3, the installation height of the seat cushion is improved under the condition that the size of the frame is not changed, and the assembly allowance below the longitudinal; the connecting support 4 capable of being connected with the cross beam pipe 3 is arranged below the cross beam pipe 3, the supporting pipe 5 which extends towards the rear upper side and is fixedly connected with the longitudinal beam 21 is arranged on the connecting support 4, the supporting pipe 5 is vertically opposite to the longitudinal beam 21, and the installation cabin 6 used for accommodating installation components is formed among the supporting pipe 5, the longitudinal beam 21 and the connecting support 4, so that an assembly area without interference can be formed on the left side and the right side of the supporting pipe 5, the longitudinal beam 21 and the connecting support 4, components such as a carbon tank or an ABS unit and the like cannot be interfered by the rear frame 2 during installation, the assembly is more convenient, the installation cabin 6 can further utilize the space among the supporting pipe 5, the longitudinal beam 21 and the connecting support 4 and has a protection effect, the connecting support is suitable for assembling components which need to be protected and have long service life, and is more. Further, the bottom of the beam tube 3 is fixedly connected with a tube column 7 extending downwards, the lower end of the tube column 7 is fixedly connected with a second transverse tube 8 extending in the left-right direction, and the upper end of the connecting support 4 is fixedly connected with the second transverse tube 8. Through linking firmly tubular column 7 in the bottom of crossbeam pipe 3, the second that makes the lower extreme of tubular column 7 link firmly the left and right directions extension violently manages 8, let the upper end and the second of linking bridge 4 violently manage 8 and link firmly, crossbeam pipe 3 and second are violently managed 8 and are only increased the width size of rear portion frame 2 front end like this, can effectively improve the regional structural strength of linking bridge 4 like this, and then guarantee the structural strength of stay tube 5 and longeron 21, and crossbeam pipe 3 and second are violently managed 8 and can carry out better protection to the part of department installation with the just right region of installation cavity, in addition because crossbeam pipe 3 and second are violently managed 8 and all be in the regional edge of assembly and can not lead to the fact obvious interference to the assembly of part, therefore can further improve the installation convenience of peripheral part under the condition of assurance intensity. The one end of crossbeam pipe 3 has the mounting groove 31 that is used for installing the middle part and hangs, and tubular column 7 has two and links firmly respectively in the second violently manage 8 both ends of controlling, and 7 upper ends of tubular column that are close to mounting groove 31 are located mounting groove 31 the place ahead and link firmly with the outer peripheral face of crossbeam pipe 3, and another tubular column 7 is towards the radial extension of crossbeam pipe 3 and with 7 along fore-and-aft direction dislocation arrangement of tubular column that are close to mounting groove 31. Through setting up two tubular columns 7 that have linked firmly between violently pipe 8 and the crossbeam pipe 3 of second, make 7 upper ends of tubular column that are close to mounting groove 31 be located mounting groove 31 the place ahead and link firmly with the outer peripheral face of crossbeam pipe 3, another tubular column 7 along fore-and-aft direction dislocation arrangement towards the radial extension of crossbeam pipe 3 and with tubular column 7 that is close to mounting groove 31, mounting groove 31 department can receive the supporting role that the middle part hung like this, tubular column 7 that is close to mounting groove 31 keeps relatively stable with the skew atress that makes the frame both sides of crossbeam pipe 3 under the condition that the installation that guarantees that the middle part hangs does not receive the interference, further improve atress stability and assembly convenience. Preferably, the dimension of the connecting bracket 4 in the left-right direction gradually increases from bottom to top, and both left and right sides of the connecting bracket 4 are arc-shaped. The size of the connecting support 4 along the left and right directions is gradually increased from bottom to top, and the left side and the right side of the connecting support 4 are arc-surface-shaped, so that the conduction stability of the load when the load passes through the connecting support 4 can be ensured, the phenomenon of unstable structure caused by stress concentration is avoided, and in addition, the size of the lower end of the connecting support 4 is smaller, and the arrangement of components is more facilitated.

As shown in fig. 1, the connecting bracket 4 includes a first enclosing plate 41 and a second enclosing plate 42 which are enclosed from left to right, through holes 43 which penetrate through and are opposite to each other in the left-right direction are respectively formed in the first enclosing plate 41 and the second enclosing plate 42, the lower end of the supporting tube 5 is located between the first enclosing plate 41 and the second enclosing plate 42, a mounting shaft 9 which extends in the left-right direction is fixedly connected to the lower end of the supporting tube 5, and two ends of the mounting shaft 9 are respectively inserted into the corresponding through holes 43 and fixedly connected to inner edges of the. Through setting up linking bridge 4 and including the bounding wall of controlling inclusion 41 and bounding wall two 42, do benefit to and reduce whole weight when guaranteeing sufficient support intensity like this, through setting up through-hole 43 at bounding wall 41 and bounding wall two 42, and make the installation axle 9 that the left and right directions that the lower extreme of stay tube 5 links firmly extend insert and locate in through-hole 43 and link firmly with the inner edge of through-hole 43, can make stay tube 5 pass through installation axle 9 and bounding wall 41 and bounding wall two 42 normal running fit earlier like this, finely tune the swing position of stay tube 5 and make it reach the most reasonable angle of connection with longeron 21, so as to ensure to make peripheral parts can have sufficient installation size between stay tube 5 and longeron 21, finally link firmly installation axle 9 and the inner edge welding of through-hole 43, can further improve the convenience of peripheral parts assembly like this. Further, the connecting bracket 4 is provided with an abdicating adjusting hole 44, the caliber size of the abdicating adjusting hole 44 is larger than the radial size of the supporting tube 5, and the supporting tube 5 penetrates through the abdicating adjusting hole 44. Through set up on linking bridge 4 and let a position transfer hole, can guarantee like this that stay tube 5 can smoothly swing in order to look for the most reasonable fixed position before linking firmly with linking bridge 4.

As shown in fig. 1 to 3, the rear end of the longitudinal beam 21 has a tilted section 211 formed by bending upward relative to the body of the longitudinal beam 21, and the upper end surface of the support tube 5 is fitted and fixedly connected to the lower surface of the tilted section 211. The tilting section 211 is arranged at the rear end of the longitudinal beam 21, so that the extending direction of the tilting section 211 is closer to the extending direction of the supporting tube 5, the welding area of the supporting tube 5 and the longitudinal beam 21 is favorably increased, and the connecting strength between the supporting tube 5 and the longitudinal beam 21 is ensured. The reinforcing plate 10 is fixedly connected to the longitudinal beam 21, the reinforcing plate 10 is U-shaped, the left inner wall and the right inner wall of the reinforcing plate 10 are fixedly connected with the left side and the right side of the longitudinal beam 21 respectively, and the bottom inner wall of the reinforcing plate 10 is fixedly connected with the outer peripheral surface of the upper end of the supporting tube 5. The U-shaped reinforcing plates 10 are fixedly connected with the left side and the right side of the longitudinal beam 21 and the outer peripheral surface of the upper end of the supporting tube 5, so that the connecting effect of the supporting tube 5 and the longitudinal beam 21 is further improved, and the structural strength is ensured. Preferably, the left side and the right side of the rear end of the longitudinal beam 21 are fixedly connected with the first tailstock 11 and the second tailstock 12 respectively, the first tailstock 11 and the second tailstock 12 are arranged in bilateral symmetry, the left inner wall and the right inner wall of the reinforcing plate 10 are fixedly connected with the outer side surface of the first tailstock 11 and the outer side surface of the second tailstock 12 respectively, and the bottom inner wall of the reinforcing plate 10 is fixedly connected with the bottom surface of the first tailstock 11 and the bottom surface of the second tailstock 12. Through the left and right sides at longeron 21 rear end link firmly first tailstock 11 and second tailstock 12 respectively, first tailstock 11 and second tailstock 12 bilateral symmetry can provide more stable support to longeron 21 with front frame 1 cooperation in the past rear end, inner wall still links firmly with the lateral surface of first tailstock 11 and the lateral surface of second tailstock 12 respectively about through setting up reinforcing plate 10, the bottom inner wall of reinforcing plate 10 still links firmly with the bottom surface of first tailstock 11 and the bottom surface of second tailstock 12, reinforcing plate 10 can tie the upper end of stay tube 5 between the bottom surface of reinforcing plate 10 and longeron 21 more steadily through the joint action of a plurality of dimensions like this, further improve structural stability.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.