CN107351775B

CN107351775B - Vehicle-mounted bicycle top frame

Info

Publication number: CN107351775B
Application number: CN201710618589.5A
Authority: CN
Inventors: 范彩霞; 张瑞翔; 张海红
Original assignee: Huanghe Science and Technology College
Current assignee: Huanghe Science and Technology College
Priority date: 2017-07-26
Filing date: 2017-07-26
Publication date: 2023-03-14
Anticipated expiration: 2037-07-26
Also published as: CN107351775A

Abstract

Vehicle-mounted bicycle roof-rack, including front beam and the rear frame that all sets up along controlling the horizontal direction, the both ends lower part of front beam and rear frame all is provided with the jack catch of fastening connection on two roof poles in car roof portion, and horizontal direction slip about along on the front beam is provided with two sets of handlebar location installation subassemblies that are used for fixed bicycle's handlebar, and horizontal direction slip about along on the rear frame is provided with two sets of rear wheel location installation subassemblies that are used for fixed bicycle's rear wheel rim. The invention fully considers the characteristics of the automobile motion process, and after the bicycle is turned upside down, the bicycle is positioned and locked by the combination of the handlebar and the rear rim, so that the positioning reliability is strong, the gravity center is greatly reduced, and the stability of the vehicle during high-speed running and turning is ensured. The bicycle clamping device can complete the positioning and clamping of the whole bicycle by only one person, is simple to use, does not need to disassemble wheels, is installed without damage, and is convenient for arranging a plurality of bicycles.

Description

Vehicle-mounted bicycle top frame

Technical Field

The invention relates to the technical field of automobile outdoor articles, in particular to a vehicle-mounted bicycle top frame.

Background

With the improvement of living standard of people, many families often take sports equipment such as mountain bicycles and the like when travelling or doing sports by self. Because the mountain bike is large in overall dimension, the mountain bike can only be fixed and supported by means of a device outside the bike body.

The traditional bicycle top frame bicycle is erected on the roof, and the position of the bicycle is limited by fixing the bicycle body at three points by using a front wheel, a rear wheel and an oblique beam (or a front fork), and the defects of the traditional bicycle top frame bicycle mainly comprise three aspects:

(1) According to the six-point positioning principle, the bicycle has six degrees of freedom in space, namely the freedom of movement in the directions of three rectangular coordinate axes of x, y and z and the freedom of rotation around the three coordinate axes. Thus, to fully define the position of the bicycle, the positioning elements should be as non-coplanar as possible. However, the three limit points of the conventional bicycle top frame are basically on a plane, and analysis is performed according to the object space positioning six-point positioning principle, so that only three degrees of freedom of six degrees of freedom of bicycle space positioning can be limited, and therefore, in the direction perpendicular to the positioning plane, all degrees of freedom of the bicycle cannot be completely limited.

(2) The bicycle is erected on the roof, the total height and the gravity center are both high, for the automobile in high-speed motion, the higher the gravity center, the poorer the stability of high-speed over-bending, the poor trafficability in a height-limited road section, and the poor stability when the automobile runs on a curve are according to the regulations of production process danger and harmful factor classification and code (GB/T13861-1992), and the over-high gravity center is a physical harmful factor which should be avoided in the motion process of the automobile.

(3) In addition, the bicycle is fixed on the roof of the automobile and is static relative to the automobile, the gravity center surface of the static bicycle is very small, almost (1000 mm (front and back) × 4mm (left and right)), when the gravity center is away from the boundary line of the width of the left and right 4mm, the bicycle falls to the left (or right), so the rollover prevention is particularly important in the design of the vehicle-mounted bicycle top frame, and the traditional bicycle top frame has poor stability because three limit points are basically on the front and back, and the limit distances on the left and right are too short (tire width or axle length).

The front wheel of the bicycle is also detached, the front fork and the rear wheel are directly fixed on the luggage rack, so that although the center of gravity is slightly lowered, the positioning point is still basically on the front and rear direction planes, the limiting distance on the left and right direction planes is still short, the front wheel of the bicycle needs to be detached before starting, the tire needs to be repeatedly installed and the brake needs to be adjusted after the front wheel of the bicycle reaches the destination, and the outdoor trip is inconvenient.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides the vehicle-mounted bicycle top frame which can reduce the gravity center of a bicycle, has strong stability and is convenient and quick to assemble and disassemble the bicycle.

In order to solve the technical problems, the invention adopts the following technical scheme: on-vehicle bicycle roof-rack, including front beam and the rear frame that all sets up along controlling the horizontal direction, the both ends lower part of front beam and rear frame all is provided with the jack catch of fastening connection on two roof poles in car roof portion, horizontal direction slip about along on the front beam is provided with two sets of handlebar location installation subassemblies that are used for fixed bicycle's handlebar, horizontal direction slip about along on the rear frame is provided with two sets of rear wheel location installation subassemblies that are used for fixed bicycle's rear rim, left a set of handlebar location installation subassembly uses with left a set of rear wheel location installation subassembly cooperation and is used for the bicycle of a location installation handstand, a set of handlebar location installation subassembly on right side uses with a set of rear wheel location installation subassembly cooperation on right side and is used for the bicycle of another handstand of location installation.

Each group of handlebar positioning and mounting assemblies comprises a handlebar left fixing piece and a handlebar right fixing piece which have the same structure; the handlebar left side mounting includes two preceding sliders and a preceding slide, a preceding slide has been seted up along controlling the horizontal direction in the front beam inside, the front beam top is seted up with preceding slide intercommunication and the preceding guide hole that equals with preceding slide hole length, the width of preceding guide hole is less than the width of preceding slide hole, the left side and the right side of preceding slide are provided with a mounting panel respectively, two preceding sliders all slide assembly in the front slide and correspond and be located a mounting panel under, every mounting panel all corresponds with a preceding slider threaded connection through a preceding slide bolt that passes preceding guide hole, preceding slide top has preceding clamp plate through the front pin axle is articulated along the rear side, connect through a fastening bolt between preceding clamp plate front side and the preceding slide top front side, a cylindrical centre gripping chamber has been seted up along the left-right direction between preceding slide top and the preceding clamp plate lower surface, the left side of handlebar stretches into the centre gripping intracavity, under fastening bolt's effect, preceding clamp plate compresses tightly the handlebar in the preceding slide top.

Each rear wheel positioning and mounting assembly comprises two rear sliding blocks and a rear sliding seat, a rear sliding hole is formed in the rear cross beam in the left-right horizontal direction, rear guide holes which are communicated with the rear sliding holes and are equal to the rear sliding holes in length are formed in the top of the rear cross beam, the width of each rear guide hole is smaller than that of each rear sliding hole, the two rear sliding blocks are assembled in the rear sliding holes in a sliding mode and are correspondingly located right below the left side and the right side of the rear sliding seat, the left side and the right side of the rear sliding seat are respectively and correspondingly connected with a rear sliding block through rear sliding bolts penetrating through the rear guide holes in a threaded mode, a left vertical plate and a right vertical plate are fixedly arranged on the top of the rear sliding seat, the lower portion of a rear wheel rim of the bicycle is in contact with the rear sliding seat and are located between the left vertical plate and the right vertical plate, the left vertical plate and the right vertical plate are vertically arranged in the front-back direction, a rear pressing plate is hinged to the top of the left vertical plate through a rear pin shaft, the right side of the rear pressing plate is located above the right vertical plate, a manual locking mechanism which is arranged on the inner side of the rear pressing plate and presses the rear rubber block downwards and positions the inner side of the left rear rubber block.

The manual locking mechanism comprises a locking screw, a handle rod, a U-shaped gasket, a lower pin shaft and an upper pin shaft, the left side is arranged in the middle of the upper end part of a right vertical plate, a lower mounting groove with the right side and the top open is formed in the middle of the right side of a rear pressing plate, a guide groove with the bottom open and the right side open is formed in the middle of the right side of the rear pressing plate, the lower pin shaft penetrates through the lower mounting groove along the front-back direction and is rotatably connected to the rear pressing plate, the outer diameter of the lower pin shaft is larger than that of the locking screw, the locking screw penetrates through the lower pin shaft along the radial direction of the lower pin shaft and is in threaded connection with the lower pin shaft, an upper mounting groove with the bottom open and the right side is formed in the middle of the right end part of the handle rod, the upper end of the locking screw penetrates through the locking screw along the front-back direction and is rotatably connected to the right end part of the handle rod, the outer diameter of the upper pin shaft is smaller than that of the locking screw, the bottom of the U-shaped gasket is fixedly connected to the upper surface of the rear pressing plate and is located right side of the guide groove, the guide groove and the guide groove are formed in a reducing structure formed in a reducing arc surface which the upper portion of the right side of the handle rod.

By adopting the technical scheme, the structure of the clamping jaws at the lower parts of the two ends of the front cross beam and the rear cross beam and the vehicle ejector rod at the top of the automobile is the prior art, detailed construction is omitted, and sliding holes and guide grooves are formed in the front cross beam and the rear cross beam along the length direction, so that the structure not only ensures the necessary strength and rigidity of the beams, but also can reduce the weight of the front cross beam and the rear cross beam, and most importantly, a sliding block can be conveniently installed in the sliding hole at the top, and all elements connected through the sliding block can slide along the axial length direction of the sliding hole to adjust the positions of the front sliding seat and the rear sliding seat on the front cross beam and the rear cross beam respectively, and are respectively positioned and fastened through the front sliding bolt and the rear sliding bolt; the fastening bolt tightly clamps the handlebar between the front sliding seat and the front pressure plate and fastens the handlebar together; the front pressing plate is hinged with the front sliding seat through a front pin shaft, and a clamping cavity matched with the outer circle of the handlebar is formed between the front pressing plate and the front sliding seat, so that the handlebar is positioned. Every bicycle handlebar both ends are furnished with left side mounting and handlebar right side mounting respectively, and preceding clamp plate and preceding slide centre gripping handlebar are as far as possible near the handlebar end for the position to the span of extension location strengthens positioning stability.

The connecting structure and the sliding positioning principle among the rear sliding bolt, the rear sliding block and the rear sliding seat are the same as those of the front sliding bolt, the front sliding block and the front sliding seat. A cavity for parking the bottom of a rear wheel rim is formed between a left vertical plate and a right vertical plate, a rear pressing plate is rotated rightwards to penetrate through spokes of the rear wheel rim, a guide groove on the right side of the rear pressing plate vertically corresponds to a lower mounting groove in the right vertical plate, a pin shaft below a handheld handle rod is used as a rotating shaft to rotate upwards, when a locking screw rod rotates to be in a vertical state, the right end part of the handle rod is located above a U-shaped gasket, the other hand presses the rear pressing plate downwards, then the handle rod is rotated to drive the locking screw rod to rotate, the locking screw rod is in threaded connection with a lower pin shaft, the right end part of the handle rod moves downwards due to rotation of the locking screw rod, when the right end part of the handle rod is in contact with the U-shaped gasket, the hand pressing the rear pressing plate is loosened, the left side lower part of the handle rod is rotated leftwards to enable the left side lower part of the handle rod to be in contact with the upper surface of a pressing plate, an arc-shaped structure which is gradually increased from the right side upper part to the left side lower part of the right end part of the outer contour of the handle rod around the center line of the upper pin shaft, the right end part of the handle rod, the handle rod rotates leftwards, the outer contour of the right end part of the handle rod can gradually press the rear pressing plate to tightly press the rear wheel rim, and firmly fix the inner side of the rear wheel rim after the rim, and press the two rubber blocks arranged on the rear pressing plate.

The top of the U-shaped washer is provided with an arc-shaped groove which is correspondingly matched with the reducing arc-shaped surface structure in a pressing fit mode, so that the structure can ensure that the locking stud cannot move rightwards to be separated from the U-shaped washer even if the automobile vibrates when running on a rugged road, and good safety and reliability are achieved.

When the bicycle is disassembled from the top of the automobile, the operation process is operated in the reverse direction, and the front pressing plate and the rear pressing plate are opened.

This on-vehicle bicycle roof-rack fully considers the characteristic of car motion process, and its on-vehicle bicycle frame design and on-vehicle luggage carrier design combine together, stand upside down the back with the bicycle upset, jointly fix a position the locking bicycle through handlebar and rear rim, and its main advantage is:

(1) The positioning is reliable, the positioning point comprises the inner side of the rear rim with self-locking performance and easy control, more importantly, the handlebar positioning and mounting assembly is arranged in the left and right directions where lateral dumping is easy to occur, therefore, the span of the positioning and clamping point in the left and right directions is about 10 times that of the traditional handlebar, the positioning point of the handlebar positioning and mounting assembly can be adjusted according to the length of the handlebar, and the application range is wide. And two bicycles can be arranged and fixed on the roof.

(2) The bicycle is installed upside down, and focus greatly reduced, the focus is about 210mm apart from the installation bottom surface, compares traditional bicycle upright loading mode, and its focus has reduced about 280mm, guarantees the stability when vehicle high speed is marchd and is turned.

(3) The positioning clamping of whole bicycle only needs alone alright completion, and is simple to use, need not dismantle the wheel, and the harmless installation is convenient for arrange many bicycles.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a left side view of FIG. 1;

FIG. 3 is a top view of FIG. 1;

FIG. 4 is an enlarged view at A of FIG. 1;

FIG. 5 is a right side elevational view of the set of rear wheel alignment mounting assemblies of FIG. 3;

fig. 6 is an enlarged view at B in fig. 5.

Detailed Description

As shown in fig. 1-6, the vehicle-mounted bicycle top frame of the present invention comprises a front cross member 1 and a rear cross member 2 both arranged along the left-right horizontal direction, the lower parts of both ends of the front cross member 1 and the rear cross member 2 are respectively provided with a claw 3 fastened to two top rods of the roof of the vehicle, two sets of handlebar positioning and mounting assemblies 4 for fixing handlebars 19 of a bicycle 7 are arranged on the front cross member 1 in a sliding manner along the left-right horizontal direction, two sets of rear wheel positioning and mounting assemblies 6 for fixing rear rims 5 of the bicycle 7 are arranged on the rear cross member 2 in a sliding manner along the left-right horizontal direction, the left set of handlebar positioning and mounting assemblies 4 and the left set of rear wheel positioning and mounting assemblies 6 are used together for positioning and mounting an inverted bicycle 7, and the right set of handlebar positioning and mounting assemblies 4 and the right set of rear wheel positioning and mounting assemblies 6 are used together for positioning and mounting another inverted bicycle 7.

Each group of handlebar positioning and mounting assemblies 4 comprises a handlebar left fixing piece 8 and a handlebar right fixing piece 9 which have the same structure; the handlebar left side fixing piece 8 comprises two front sliders 10 and a front sliding seat 11, a front sliding hole 12 is formed in the front cross beam 1 in the left-right horizontal direction, a front guide hole 13 which is communicated with the front sliding hole 12 and has the same length with the front sliding hole 12 is formed in the top of the front cross beam 1, the width of the front guide hole 13 is smaller than that of the front sliding hole 12, mounting plates 14 are respectively arranged on the left side and the right side of the front sliding seat 11, the two front sliders 10 are assembled in the front sliding hole 12 in a sliding mode and are correspondingly located under the mounting plate 14, each mounting plate 14 is correspondingly in threaded connection with one front slider 10 through a front sliding bolt 15 penetrating through the front guide hole 13, the top of the front sliding seat 11 is hinged to a front pressing plate 17 through a front pin shaft 16 in the rear side, the front side of the front pressing plate 17 is connected with the front side of the top of the front sliding seat 11 through a fastening bolt 18, a cylindrical clamping cavity is formed between the top of the front sliding seat 11 and the lower surface of the front pressing plate 17 in the left-right direction, the left side of the handlebar 19 extends into the clamping cavity, and the handlebar 19 is tightly pressed on the front sliding seat 11 by the front pressing plate 17 under the effect of the fastening bolt 18.

Each set of rear wheel positioning and mounting assembly 6 comprises two rear sliders 20 and a rear slide seat 21, a rear slide hole 22 is formed in the rear cross beam 2 in the left-right horizontal direction, a rear guide hole 23 which is communicated with the rear slide hole 22 and has the same length as the rear slide hole 22 is formed in the top of the rear cross beam 2, the width of the rear guide hole 23 is smaller than that of the rear slide hole 22, the two rear sliders 20 are assembled in the rear slide hole 22 in a sliding manner and are correspondingly positioned right below the left side and the right side of the rear slide seat 21, the left side and the right side of the rear slide seat 21 are respectively and correspondingly in threaded connection with the rear slider 20 through a rear slide bolt 24 penetrating through the rear guide hole 23, a left vertical plate 25 and a right vertical plate 26 are fixedly arranged at the top of the rear slide seat 21, the lower portion of the rear rim 5 of the bicycle 7 is in contact with the rear slide seat 21 and is positioned between the left vertical plate 25 and the right vertical plate 26, the left vertical plate 25 and the right vertical plate 26 are both vertically arranged in the front-back direction, the top of the left vertical plate 25 is hinged with a rear pressing plate 28, the right pressing plate 28 is positioned above the right vertical plate 26, a rear rubber block 29 is arranged on the rear pressing mechanism, and a rear rubber block 31 is arranged on the rear rubber block 31 which presses the rear rubber block 5.

The manual locking mechanism 29 comprises a locking screw 32, a handle bar 33, a U-shaped gasket 34, a lower pin shaft 35 and an upper pin shaft 36, a lower mounting groove with left, right and top openings is arranged in the middle of the upper end part of the right vertical plate 26, a guide groove with top openings, bottom openings and right openings is arranged in the middle of the right side of the rear pressing plate 28, the lower pin shaft 35 penetrates through the lower mounting groove along the front-back direction and is rotatably connected to the rear pressing plate 28, the outer diameter of the lower pin shaft 35 is larger than that of the locking screw 32, the locking screw 32 penetrates through the lower pin shaft 35 along the radial direction of the lower pin shaft 35 and is in threaded connection with the lower pin shaft 35, an upper mounting groove with bottom openings and right openings is arranged in the middle of the right end part of the handle bar 33, the upper end of the locking screw 32 is positioned in the upper mounting groove, the upper pin shaft 36 penetrates through the locking screw 32 along the front-back direction and is rotatably connected to the right end part of the handle bar 33, the outer diameter of the upper pin shaft 36 is smaller than that of the locking screw 32, the bottom of the U-shaped gasket 34 is fixedly connected to the upper surface of the rear pressure plate 28 and is positioned right above the guide groove, the U-shaped gasket 34 is through from top to bottom and is open at the right side, the upper mounting groove, the inner hole of the U-shaped gasket 34, the guide groove and the lower mounting groove are sequentially corresponding to each other from top to bottom, when the locking screw 32 is in a vertical state, the locking screw 32 is sequentially positioned in the upper mounting groove, the U-shaped gasket 34, the guide groove and the lower mounting groove from top to bottom, the outline of the right end of the handle rod 33 is of a reducing arc-shaped structure 37 which is gradually increased from the upper right side to the lower left side around the central line of the upper pin shaft 36, and the top of the U-shaped gasket 34 is provided with an arc-shaped groove 38 which is correspondingly matched with the reducing arc-shaped structure 37 in a crimping manner.

The structure of the jack catch 3 and the roof bar of the car top of both ends of front beam 1 and rear beam 2 is prior art, the concrete structure is not repeated any more, have slide holes and guide slots on front beam 1 and rear beam 2 along the length direction, this kind of structure has already guaranteed the necessary intensity and rigidity of roof beam, can lighten the weight of front beam 1 and rear beam 2, it is convenient to mount the slide block in the slide hole of the top most important, make all elements connected through the slide block can slide along axial length direction of the slide hole in order to adjust the front slide 11 and rear slide 21 in the position of front beam 1 and rear beam 2 separately, and position and fasten separately through front sliding bolt 15 and rear sliding bolt 24; the fastening bolt 18 tightly clamps the handlebar 19 between the front slide 11 and the front press plate 17 and fastens them together; the front pressing plate 17 is hinged with the front sliding seat 11 through a front pin shaft 16, and a clamping cavity matched with the excircle of the handlebar 19 is formed between the front pressing plate 17 and the front sliding seat 11 together to realize the positioning of the handlebar 19. The two ends of a handlebar 19 of each bicycle 7 are respectively provided with a left side fixing piece and a right side fixing piece 9 of the handlebar, and a front pressing plate 17 and a front sliding seat 11 clamp the handlebar 19 as close to the end of the handlebar 19 as possible, so that the positioning span is lengthened, and the positioning stability is enhanced.

The connecting structure and the slide positioning principle among the rear slide bolt 24, the rear slider 20 and the rear slide 21 are the same as those of the front slide bolt 15, the front slider 10 and the front slide 11. A cavity parked at the bottom of the rear rim 5 is formed between the left vertical plate 25 and the right vertical plate 26, the rear pressing plate 28 rotates rightwards to penetrate through spokes of the rear rim 5, a guide groove on the right side of the rear pressing plate 28 vertically corresponds to a lower mounting groove on the right vertical plate 26, the handle rod 33 is held by a hand and rotates upwards by taking the lower pin shaft 35 as a rotating shaft, when the locking screw 32 rotates to a vertical state, the right end part of the handle rod 33 is positioned above the U-shaped gasket 34, the other hand presses the rear pressing plate 28 downwards, then the handle rod 33 rotates to drive the locking screw 32 to rotate, the right end part of the handle rod 33 moves downwards due to the rotation of the locking screw 32 and the lower pin shaft 35, when the right end part of the handle rod 33 is in contact with the U-shaped gasket 34, the hand pressing the rear pressing plate 28 is released, the pressing rod 33 rotates leftwards to enable the lower part on the left side of the handle rod 33 to be in contact with the upper surface of the handle plate, and as the outer contour of the right end part of the handle rod 33 surrounds the central line of the upper pin 36, a cambered surface of the left side upper part is in a gradually increased arc-shaped structure 37, the left side of the rear rim, the rear pressing plate is tightly pressed by the rubber block 31 of the rear pressing rubber block 31, and the rear pressing plate 5.

The top of the U-shaped washer 34 is provided with an arc groove 38 which is correspondingly engaged and in press fit with the reducing arc structure 37, and the structure can ensure that the locking stud cannot move rightwards to be separated from the U-shaped washer 34 when the automobile runs on a rugged road to generate vibration, thereby achieving good safety and reliability.

When the bicycle 7 is disassembled from the roof of the automobile, the operation process is operated in the reverse direction, and the front pressing plate 17 and the rear pressing plate 28 are opened.

The present embodiment is not intended to limit the shape, material, structure, etc. of the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention are within the scope of the technical solution of the present invention.

Claims

1. On-vehicle bicycle roof-rack, including all along front beam and the rear frame member that controls the horizontal direction setting, the both ends lower part of front beam and rear frame member all is provided with the jack catch of fastening connection on two car ejector pins in car roof portion, its characterized in that: two groups of handlebar positioning and mounting assemblies for fixing handlebars of the bicycle are arranged on the front cross beam in a left-right horizontal direction in a sliding manner, two groups of rear wheel positioning and mounting assemblies for fixing a rear rim of the bicycle are arranged on the rear cross beam in a left-right horizontal direction in a sliding manner, one group of handlebar positioning and mounting assemblies on the left side are matched with one group of rear wheel positioning and mounting assemblies on the left side for positioning and mounting one inverted bicycle, and one group of handlebar positioning and mounting assemblies on the right side are matched with one group of rear wheel positioning and mounting assemblies on the right side for positioning and mounting the other inverted bicycle;

each group of handlebar positioning and mounting assemblies comprises a handlebar left fixing piece and a handlebar right fixing piece which have the same structure; the handlebar left side fixing piece comprises two front sliding blocks and a front sliding seat, a front sliding hole is formed in the front cross beam in the left-right horizontal direction, a front guide hole which is communicated with the front sliding hole and has the same length with the front sliding hole is formed in the top of the front cross beam, the width of the front guide hole is smaller than that of the front sliding hole, a mounting plate is arranged on each of the left side and the right side of the front sliding seat respectively, the two front sliding blocks are assembled in the front sliding hole in a sliding mode and are correspondingly positioned under the mounting plate, each mounting plate is correspondingly in threaded connection with one front sliding block through one front sliding bolt penetrating through the front guide hole, a front pressing plate is hinged to the top of the front sliding seat along the rear side through a front pin shaft, the front side of the front pressing plate is connected with the front side of the top of the front sliding seat through one fastening bolt, a cylindrical clamping cavity is formed between the top of the front sliding seat and the lower surface of the front pressing plate in the left-right direction, the left side of the handlebar extends into the clamping cavity, and the front sliding seat tightly presses the handlebar on the top of the front sliding seat under the action of the fastening bolt;

each group of rear wheel positioning and mounting assemblies comprises two rear sliding blocks and a rear sliding seat, a rear sliding hole is formed in the rear cross beam along the left-right horizontal direction, a rear guide hole which is communicated with the rear sliding hole and has the same length as the rear sliding hole is formed in the top of the rear cross beam, the width of the rear guide hole is smaller than that of the rear sliding hole, the two rear sliding blocks are assembled in the rear sliding hole in a sliding mode and are correspondingly positioned right below the left side and the right side of the rear sliding seat, the left side and the right side of the rear sliding seat are correspondingly in threaded connection with one rear sliding block through a rear sliding bolt penetrating through the rear guide hole respectively, a left vertical plate and a right vertical plate are fixedly arranged on the top of the rear sliding seat, the lower portion of a rear wheel rim of a bicycle is in contact with the rear sliding seat and positioned between the left vertical plate and the right vertical plate, the left vertical plate and the right vertical plate are vertically arranged along the front-back direction, a rear pressing plate is hinged to the top of the left vertical plate through a rear pin shaft, the right side of the rear pressing plate is positioned above the right vertical plate, a manual locking mechanism is arranged on the right vertical plate, a left rubber block and a left rubber block is arranged on the lower surface of the rear pressing plate, and presses the inner side of the rear rubber block downwards;