Double-rear-wheel double-drive double-brake gear change interactive pull type bicycle

Abstract

The invention discloses a double-rear-wheel double-drive double-brake gear speed change interactive pull type bicycle which comprises a bicycle body, a girder assembly, a gearbox, a motor, a rear axle assembly, a rear wheel assembly, a rear riding saddle, a band-type brake, a battery, other accessories and fasteners. The large beam assembly is fixed to a middle connector of the bicycle body and the joint of a vertical fork and a large beam through long hexagonal bolts, a gearbox is installed below the bicycle body, and the motor is installed between the gearbox and the rear shaft assembly and inserted into special-shaped holes of the left rear beam and the right rear beam through shaft extensions on the two sides to be fixed. The invention belongs to the technical field of the bicycle industry in vehicles, and particularly relates to a double-rear-wheel double-drive double-brake gear speed change interactive pull type bicycle. The problems that a traditional tandem bicycle is long in total length, large in occupied parking space, poor in stability, prone to lateral deviation and toppling and the like are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of the bicycle industry in the category of transportation means, and specifically refers to a double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, towable bicycle. Background Art

[0002] In the field of transportation means, the bicycle industry has always occupied an important position. The annual output of electric bicycles in China exceeds 10 million, and a large number of them are exported. With the development of the times, traditional bicycles have gradually been replaced by electric bicycles and shared bicycles. Although double-person bicycles can generate double driving forces, due to their long body, poor stability, and high price, their applications are limited to places such as parks. Although four-wheel multi-person bicycles are safe and comfortable and are mostly used for leisure and entertainment, their functions are relatively single. Although large-scale fun gathering bicycles have strong entertainment and are suitable for scenarios such as celebrations and exhibitions, they cannot meet the daily travel and diverse needs of the public. At the same time, people's demands for bicycles are becoming increasingly diversified. They not only expect bicycles to have stronger practicality to meet the needs of multi-person travel and carrying goods, but also hope that they have higher safety and maneuverability. Against this background, the double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, towable bicycle has emerged. It combines features such as a double-rear-wheel design to enhance stability, double-person double-drive to increase power, a double-brake system to ensure safety, gear shifting to adapt to different road conditions, and a towing function to meet the needs of carrying goods, aiming to make up for the deficiencies of existing bicycle products, provide users with a more efficient, safe, and multi-functional riding experience, explore the application possibilities of bicycles in multiple scenarios such as leisure travel and short-distance transportation, and promote the bicycle industry to develop in a more professional and diversified direction. Summary of the Invention

[0003] In view of the above situation, to overcome the defects of the prior art, the present invention provides a double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, towable bicycle, effectively solving the problems in the current market that the total vehicle body length is relatively long, occupying a large parking space, the vehicle stability is poor, and it is easy to have phenomena such as side deviation and tipping.

[0004] The technical solution adopted by the present invention is as follows: The present invention provides a double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, towable bicycle, including a complete bicycle. The complete bicycle includes components such as a bicycle main body, a beam assembly, a gearbox, a motor, a rear axle assembly, a rear wheel assembly, a rear saddle, a band brake, a battery, and other accessories and fasteners. The beam assembly is fixed to the connection between the middle joint of the bicycle main body and the fork and the beam through hexagon long bolts;

[0005] A gearbox is installed below the bicycle main body. The motor is installed between the gearbox and the rear axle assembly. The motor is fixed by inserting the shaft extensions on both sides into the special-shaped holes of the left rear beam and the right rear beam. The rear axle assembly is provided with a brake drum assembly and a flywheel assembly. A touch brake is provided at the front of the main beam. A brake handle is provided in front of the bicycle main body for braking the brake drum on the rear axle assembly.

[0006] Further, the main beam assembly consists of components such as a left rear beam, a right rear beam, end plates, brackets, etc. and fastening components, forming a semi-closed rectangular main beam. Blanking and punching are provided on both the left rear beam and the right rear beam, and the flanging directions are opposite. Accessories such as warning lighting fixtures and vehicle license plates can be installed at the tail of the main beam assembly.

[0007] Further, a small sprocket II is installed on the gearbox. A bearing seat and a middle shaft are installed on the main beam assembly. A large sprocket assembly with a crank pedal is installed on the right side of the middle shaft. A small sprocket II and a chain are provided on the gearbox. The small sprocket II and the chain form a sprocket-chain transmission pair. A large sprocket II is installed on the output shaft of the gearbox. The large sprocket II and a large sprocket I installed on the rear axle assembly form a forward sprocket-chain transmission pair through a chain. A middle chain is installed on the output shaft on the right side of the gearbox. The chain on the gearbox and the large sprocket I form a reverse sprocket-chain transmission pair.

[0008] Further, the motor is installed in the middle of the main beam assembly, between the gearbox and the rear axle. A throttle grip is provided on the motor. The two ends of the rear axle are respectively inserted into the special-shaped holes of the left and right rear beams and fixed by nuts. The end of the rear axle with a wire is arranged on the right rear beam.

[0009] Further, the rear axle is installed at the rear D holes of the left rear beam and the right rear beam and fixed by a hexagon bolt assembly I. A drum wheel assembly is installed on the rear axle. The drum wheel assembly includes a brake pot and a large sprocket I. Two sets of flywheels I are screwed and installed on the rear axle through a threaded sleeve. A spacer sleeve and a washer are provided on the rear axle for axial limit. A flat key I and a flat key II provided on the rear axle are used for circumferential positioning. Two sets of rear wheel assemblies are installed on the shaft extensions on both sides of the rear axle and fixed by nuts. A bearing is provided on the rear axle. A set screw is provided in the inner ring of the bearing. The outer ring of the bearing is used to install a bearing seat through a clamping plate with a threaded hole.

[0010] Further, the rear wheel assembly includes a hub barrel, a chrome-plated steel rim, steel wire spokes, connecting nuts, an outer tire, and an inner tire. A flywheel II is installed on the outside of the hub barrel, and a flywheel III is installed on the inside of the hub barrel.

[0011] Further, a front saddle is additionally provided on the main beam assembly. A steel pipe is provided below the front saddle. Threads are provided above the steel pipe. The height of the front saddle can be adjusted by a lock nut. A platform is milled at the lower end of the steel pipe, and the positioning of the steel pipe in the circumferential direction is realized through a pressing plate, so that the front saddle cannot rotate randomly. A spring shock absorption assembly and a compression spring are arranged inside the front saddle to form a double shock absorption device. A bracket is installed at the tail of the main beam assembly. The bracket, the left rear beam and the right rear beam are connected to the rear vehicle through a hexagon bolt assembly II. The pressing plate is fixed through a screw assembly. The steel pipe is locked through an opening pin.

[0012] Further, the brake system includes components such as a brake drum, a leather strip, a leather sheath, a connecting rod, a U-shaped brake lever I, a handle I, a pressing plate and a return spring. The U-shaped brake lever I is located at the front end of the main beam assembly and straddles both sides of the front tube of the vehicle frame. The fulcrum is arranged on the connecting rod to form a lever system. When the handle I is pulled backward, the leather strip can be tightened to wrap around the brake drum, braking the rear axle and two groups of rear wheel assemblies. One end of the return spring is fixedly connected to the flanging of the end plate. The pin shaft of the U-shaped brake lever I plays a limiting role.

[0013] Further, the U-shaped lever II is located at the very front end of the main beam assembly and straddles both sides of the front tube of the vehicle frame. The fulcrum K is located on the connecting rod to form a lever system. When the handle II is pushed, the contact brake can be pushed forward. When it contacts the outer tire of the front wheel, it can play a braking role. The other end of the return spring is fixed to the connecting rod at the fulcrum L of the U-shaped brake lever I.

[0014] Further, a bottom bracket is installed at the C hole at the front end of the main beam assembly. The bearing seat is fixed to the left rear beam and the right rear beam through a hexagon bolt assembly III. Two groups of platforms with opposite directions are milled at both ends of the bottom bracket, and the right crank sprocket and the left crank are fixed through a positioning pin. The bottom bracket, the U-shaped lever II and the U-shaped brake lever I installed at the front end of the main beam assembly have an anti-collision effect on the front fork.

[0015] The beneficial effects achieved by the present invention with the above structure are as follows: This solution proposes a double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, towed bicycle. Through the simply supported beam structure of the double rear wheels with a narrow wheelbase, it realizes functions such as convenient parking, novice learning to ride, as well as double drive, double brake, interaction, and towing of the vehicle. This method solves the problem of the comfort of the rear seat passengers, improves and enhances the power performance and adaptability of the vehicle, increases the grip of the wheels on the ground, prevents phenomena such as wheel skidding and idling of the vehicle in rainy and snowy weather, occupies a smaller parking space, has high vehicle stability, and strong interactivity. Description of the Drawings

[0016] Figure 1Schematic diagram of the overall external structure of a double-rear-wheel bicycle of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention;

[0017] Figure 2 Schematic diagram of the beam structure of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention;

[0018] Figure 3 Schematic diagram of the connection of the gearbox and the sprocket chain transmission pair of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention;

[0019] Figure 4 Schematic diagram of the motor of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention;

[0020] Figure 5 Schematic diagram of the rear axle structure of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention;

[0021] Figure 6 Schematic diagram of the rear wheel hub barrel structure of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention;

[0022] Figure 7 Schematic diagram of the saddle structure of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention;

[0023] Figure 8 Schematic diagram of the rod-type band brake structure of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention;

[0024] Figure 9 Schematic diagram of the rod-type touch brake structure of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention;

[0025] Figure 10 Schematic diagram of the middle axle structure of a double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, towed bicycle proposed by the present invention.

[0026] Among them, 000 is the complete bicycle; 100 is the bicycle main body; 110 is the expanding brake; 011 is the large sprocket assembly; 012 is the second small sprocket; 013 is the chain; 014 is the second large sprocket; 015 is the chain; 016 is the middle chain; 017 is the chain; 200 is the main beam assembly; 201 is the left rear beam; 202 is the right rear beam; 203 is the end plate; 204 is the bracket; 205 is the middle shaft bushing; 206 is the middle shaft; 207 is the cushion sleeve; 208 is the bearing seat; 221 is the hexagon bolt assembly III; 300 is the gearbox; 400 is the motor; 401 is the motor main body; 402 is the first small sprocket; 403 is the controller; 404 is the throttle grip; 405 is the power display device; 500 is the rear axle assembly; 501 is the rear axle; 502 is the bearing; 503 is the drum assembly; 504 is the brake drum; 505 is the first large sprocket; 506 is the threaded sleeve; 507 is the first flywheel; 508 is the cushion sleeve; 509 is the washer; 510 is the splint; 521 is the first flat key; 522 is the second flat key; 523 is the hexagon bolt assembly I; 600 is the rear wheel assembly; 601 is the hub shell; 602 is the second flywheel; 603 is the fixing sleeve; 604 is the third flywheel; 605 is the chrome-plated steel rim; 606 is the steel wire spoke; 607 is the connecting nut; 608 is the outer tire; 609 is the inner tube; 006 is the rear wheel fender; 060 is the crank assembly; 007 is the backrest member; 700 is the rear saddle; 701 is the front saddle; 702 is the steel pipe; 703 is the compression spring; 704 is the lock nut; 706 is the pressing plate; 721 is the hexagon bolt assembly II; 722 is the screw assembly; 723 is the split pin; 800 is the band brake; 801 is the leather strip; 802 is the leather sheath; 803 is the connecting rod; 804 is the first U-shaped brake handle; 805 is the first handle; 806 is the pressing plate; 807 is the return tension spring; 808 is the pin shaft; 810 is the contact brake; 814 is the second U-shaped brake handle; 815 is the second handle; 900 is the battery.

[0027] The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. Detailed implementation manners

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0030] As Figures 1 - 10 shown, the present invention provides a double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, trailer-type bicycle. The whole bicycle 000 mainly consists of bicycle main body 100, beam assembly 200, gearbox 300, motor 400, rear axle assembly 500, rear wheel assembly 600, rear saddle 700, band brake 800, battery 900 and other components, as well as other accessories and fasteners. The beam assembly 200 is fixed to the connection between the middle joint and the vertical fork of the bicycle main body 100 and the beam by M10×180 hexagon long bolts. The newly established middle joint is moved forward by 60 mm, and the center of the rear axle fixing the left and right groups of rear wheels is moved backward by 90 mm. At the same time, it is ensured that the front and rear sets of pedals will not touch each other or the front wheel during operation. The total length of the vehicle body (excluding the protruding part at the end of the beam) is only increased by 90 mm compared with the original length of the whole vehicle, about 2 m. The gearbox 300 is installed below the bicycle main body 100, providing a basic supporting function for the beam. When shifting gears, the shift handle should be staggered from the vertical pipe of the frame. Therefore, there is an appropriate eccentricity between the central axes of the bicycle main body 100 and the beam. The motor 400 of the bicycle main body 100 is installed between the gearbox 300 and the rear axle assembly 500. The motor 400 is fixed by inserting the shaft extensions on both sides into the special-shaped holes of the left rear beam 201 and the right rear beam 202. There is a gap of about 10 mm between the motor and the front wheel tire when static. It is dedicated to braking the front wheel, and together with the bumper on the front fork, it forms a double insurance function. The rear axle assembly 500 is provided with a brake drum assembly and a flywheel assembly. A touch brake is provided at the front part of the beam. A brake handle is provided in front of the bicycle main body 100 for braking the brake drum on the rear axle assembly 500. A belt band brake structure is adopted, with large braking force and capable of braking both rear wheels simultaneously, that is, the so-called double brake. When the vehicle speed is not high, only braking the front wheel touch brake can be used as an auxiliary brake. The lithium battery assembly can be installed in the space at the rear part of the beam, including accessories such as a controller. A rectangular bracket is embedded at the end of the beam for inserting the front saddle 701, which is equipped with spring shock absorption and height adjustment devices. There is also a pin hole for connecting the trailer vehicle on the bracket. The distance between the center lines of the two groups of rear wheels on both sides of the beam is about 280 mm, and each is equipped with its own wheel cover 006, which is fixed on both sides of the beam. A luggage rack is provided on the rear seat and is supported by a vertical rod connected to the beam, which can be used to place personal luggage and items.

[0031] The main beam assembly 200 consists of components such as the left rear beam 201, right rear beam 202, end plate 203, bracket 204, etc. and fastening components, forming a semi-closed rectangular main beam. It is made of cold-rolled steel plates with a thickness of 1.5 - 2 mm. Blanking and punching are provided on both the left rear beam 201 and the right rear beam 202, and the flanging directions are opposite, which can ensure the concentricity between the holes on both sides and has sufficient mechanical strength and is not easily deformed. The transmission 300 has a certain supporting effect and is fixed with M10X20 hexagon bolts on both sides. The F hole is the input shaft, and the G hole is the output shaft. The middle joint of the whole vehicle is located at the A hole, the vertical fork (rear axle) is located at the B hole, and the luggage rack support rod is located at the M hole, with a total of three connections to the main beam. The motor 400 is installed at the E hole position. The special-shaped hole has a self-locking positioning function. The new middle joint position is at the C hole (Φ40mm) for installing a stamping type PF204 spherical deep groove ball bearing seat, and the original middle joint position at the A hole is translated 60 mm forward so that the toes will not touch the front wheel edge when stepping on. The new rear axle position is at the D hole (Φ40mm), using a PF204 type bearing, and the original rear axle position at the B hole is translated 90 mm backward. The bearing seat is fixed with a set of 3 M8X20 hexagon bolts and is the main stress point. The two long slots on the end plate are used to insert the stainless steel brake. The support point position is located at the K hole, and the support point position of the brake 800 is located at the L hole. The H hole is used to connect the two-wheel trailer. The steel pipe 702 of the front saddle 701 newly added at the rear of the luggage rack can be inserted into the J hole above the bracket. Warning lighting fixtures and vehicle license plates and other accessories can be installed at the tail of the main beam assembly 200.

[0032] The input shaft F of the gearbox 300 is located on the right side and is a spline shaft with a diameter of Φ20mm. A small sprocket two 012 with 16 teeth is installed on the gearbox 300. A PF204 type bearing seat 208 and a middle shaft 206 are installed at the position of the newly established middle joint C hole of the beam assembly 200. A large sprocket assembly 011 with a crank pedal is installed on the right side of the middle shaft 206. A small sprocket two 012 and a chain 013 are arranged on the gearbox 300. The small sprocket two 012 and the chain 013 form a sprocket-chain transmission pair. The center distance is about 260mm, the transmission ratio is 3:1, and it is a short-chain transmission. The output shaft G of the gearbox is located on the left side and is a spline shaft with a diameter of Φ25mm. A large sprocket two 014 is installed on the output shaft of the gearbox 300. The large sprocket two 014 and a large sprocket one 505 installed on the rear axle assembly 500 form a forward sprocket-chain transmission pair through a chain 015. The center distance is about 320mm, the transmission ratio is 3:1, and it belongs to a short-chain transmission. The cumulative speed-up ratio of the two-stage transmission is 9:1. Since the reduction ratio of the quick gear of the reduction box is 4.5, the actual speed-up ratio from the middle shaft to the rear axle is 2 times, slightly less than the common speed ratio of 2.2 - 2.5 times of ordinary bicycles. The maximum speed is about 20km / h. For a double-rear-wheel bicycle with a reverse function, a gearbox with a double output shaft is adopted. A 24-tooth middle chain 016 is installed on the output shaft on the right side of the gearbox 300, and it adopts a Φ25mm spline connection method. The chain 017 on the gearbox 300 and the large sprocket one 505 form a reverse sprocket-chain transmission pair. The center distance is also about 320mm, the transmission ratio is 1.5:1, and the cumulative speed-up ratio of the two-stage transmission is 4.5:1. Since the reduction ratio of the reverse gear of the reduction box is 16, the actual speed ratio from the middle shaft to the rear axle is 1:3.55, changing from speed-up to deceleration. The vehicle speed during reverse is only one-seventh of that during forward fast gear.

[0033] Motor 400 is a brushless high-speed planetary gear reduction motor with the characteristics of small size, light weight, fast starting and large torque. It has a rated power of 250W, a rated voltage of 48V, a gear opening size of 126mm, and can be ridden with pedals. The motor is installed in the center of the rear wheel and is connected to the wheel hub through the surrounding steel spokes. The biggest advantage of this motor is that it has M35X1 British fine-pitch threads on both sides of the motor, which can be used to install flywheels and expansion brakes. The gear opening size is 126mm, which is smaller than the 136mm gear opening size of the main beam, allowing a certain amount of adjustment room. The motor 400 is installed in the middle of the beam assembly 200, and is set between the gearbox 300 and the rear axle 501. The two ends of the rear axle 501 are respectively inserted into the special-shaped holes of the left and right rear beams and fixed by M14 nuts. The end of the rear axle 501 with the wire is set on the right rear beam 202. Both flywheels use 22-tooth high-strength flywheels for tricycles with a long service life. The flywheel on the left is connected to the 40-tooth large sprocket on the rear axle through a chain to output torque. The reduction ratio is close to 2 times, and the torque acting on the rear axle is also close to doubled, but the vehicle speed is For safety reasons, the maximum speed during electric assist should not exceed 20 km / h. When the human-driven mode is adopted, the motor 400 will be in a stationary state due to the overrunning effect of the flywheel, which can avoid the load being increased by the magnetic damping generated by the motor. The flywheel on the right is used to input torque. The motor 400 weighs 2.8 kg and is installed in the belly of the frame in an internal manner. It can cope with harsh terrain conditions and states such as uphill, headwind and heavy load, but it is only electric-assisted, not pure electric, and is essentially different from an electric bicycle.

[0034] The rear axle 501 is installed at the rear D holes of the left rear beam 201 and the right rear beam 202, supported by a stamping type PF204 spherical plain bearing housing 502, and fixed by 3 to 4 M8X20 hex bolt assemblies. A drum assembly 503 is installed on the rear axle 501. The drum assembly 503 includes a brake drum 504 and a 40-tooth large sprocket one 505, which are welded into one body, having two functions of inputting the torque from the motor and braking. It has a compact structure and can reduce the speed of the motor by nearly half. Therefore, nearly double the torque can be obtained on the rear axle. The brake formed by a brake drum with a large diameter of Φ136mm and a width of 43mm and a cowhide belt has the advantages of simple structure and large braking force. Two sets of flywheels one 507 are screwed and installed on the rear axle 501 through a threaded sleeve 506. Its functions are to input the external power from the towed vehicle and can also be used to install a Φ110mm brake drum or a disc, adding a set of brake or expansion brake auxiliary braking device, which is operated by a wire cable pulled to the handlebar of the faucet. The high-strength rear axle with a diameter of Φ25mm can bear a large load and torque, but is not easy to be damaged and has a long service life. A spacer sleeve 508 and a washer 509 are arranged on the rear axle 501 for axial limit, and a flat key one 521 and a flat key two 522 arranged on the rear axle 501 are used for circumferential positioning. Two sets of rear wheel assemblies 600 are installed on the two side shaft extensions of the rear axle 501. The shaft diameter of the joint part is Φ16mm and is fixed by an M16 nut. It is convenient for installation and disassembly, can be connected to the rear axle and is convenient for assembly and disassembly. A bearing 502 is arranged on the rear axle 501. A set screw is arranged on the inner ring of the bearing 502, and the outer ring of the bearing 502 is used to install a bearing seat 208 through a clamping plate 510 with a screw hole.

[0035] The rear wheel assembly 600 includes a hub barrel, a chrome-plated steel rim 605, steel wire spokes 606, a connecting nut 607, an outer tire 608 and an inner tire 609. The rear wheel uses a 40-hole hub barrel, and the outer diameter of the middle barrel is more than Φ20mm, which is used to fit into the Φ16mm shaft shoulder parts at both ends of the rear axle and is connected by an 8mm flat key. A 22-tooth flywheel two 602 is installed on the outside of the hub barrel, and a 16-tooth flywheel three 604 is installed on the inside of the hub barrel.

[0036] The main beam assembly 200 is additionally provided with a front saddle 701, which facilitates the interaction between the front seat personnel and the rear seat personnel. A steel pipe 702 is arranged below the front saddle 701. Threads are provided above the steel pipe 702. The height of the front saddle 701 can be adjusted by a lock nut 704 on the steel pipe 702. The maximum adjustment range is 100 mm. A platform is milled at the lower end of the steel pipe 702, and the circumferential positioning of the steel pipe 702 is achieved through a pressing plate 706, so that the front saddle 701 cannot rotate randomly. A spring shock absorption assembly and a compression spring 703 are arranged inside the front saddle 701 to form a double shock absorption device, which can reduce the impact load on the main beam and prevent deformation, and at the same time ensure the comfort of the rear seat passengers. A bracket 204 is installed at the tail of the main beam assembly 200, which provides basic support for the main beam and bears the weight of the rear saddle users. At the same time, it is also used for the connection of towing the rear vehicle. The bracket 204, the left rear beam 201 and the right rear beam 202 are connected to the rear vehicle through an M10X20 hexagon bolt assembly two 721. The pressing plate 706 is fixed through an M6X12 screw assembly 722. The steel pipe 702 is locked through a split pin 723. The distance from the lower end of the steel pipe to the ground when the saddle is adjusted to the lowest position shall not be less than 100 mm.

[0037] The brake system includes components such as a brake drum 504, a leather strap 801, a leather sheath 802, a connecting rod 803, a U-shaped brake lever one 804, a handle one 805, a pressing plate 806 and a return spring 807. The U-shaped brake lever one 804 is located at the front end of the main beam assembly 200 and straddles both sides of the front tube of the frame. The fulcrum is arranged on the connecting rod 803 to form a lever system. When the handle one 805 is pulled backward, the leather strap 801 can be tightened to wrap around the brake drum 504, braking the rear axle 501 and two groups of rear wheel assemblies 600, thus braking the rear axle and two groups of rear wheels. One end of the return spring 807 is fixedly connected to the flanging of the end plate 203, and the pin shaft 808 of the U-shaped brake lever one 804 plays a limiting role.

[0038] The U-shaped brake handle two 814 is located at the very front end of the main beam assembly 200, spanning both sides of the front frame tube. The fulcrum K is located on the connecting rod 803 to form a lever system. When the handle two 815 is pushed, the contact brake 810 can be pushed forward. When it touches the outer tire of the front wheel, it can play a braking role. The other end of the return spring 807 is fixed on the connecting rod 803 at the fulcrum L of the U-shaped brake handle one 804. The contact brake plays a limiting role, that is, the inner surface of the contact brake coincides with the outer surface of the end plate 203. The maximum rotation angle of the U-shaped brake handle is about ±15 degrees. Since the braking radius dimension is relatively large and equal to the radius of the front wheel, the friction coefficient between the stainless steel material of the contact brake and the rubber texture outer tire is also relatively large. The width of the contact brake handle is about 80 mm, and the hand feeling when holding it is relatively comfortable. It is located inside the holding brake handle and is inclined backward at an angle of about 15 degrees, and can be operated independently. The braking of the contact brake on the front wheel is generally more suitable for conventional braking when the vehicle speed is not high. Since the bending moment generated on the front fork is relatively large and it is easy to deform, the contact brake and the main beam play a certain protective role for the front fork, so the insurance function is increased. The front wheel contact brake is only applicable to the braking when the front wheel is in the central and middle position. When the vehicle turns, since the front wheel deviates from the center of the contact brake, it will become ineffective, and other braking methods such as rear wheel braking should be adopted.

[0039] The central shaft 206 is installed at the C hole at the front end of the main beam assembly 200. The bearing seat 208 adopts the triangular stamping type spherical roller bearing seat of deep groove type, model PFT204, and is fixed on the left rear beam 201 and the right rear beam 202 by 3 M8X20 hexagon bolt assemblies three 221. The central shaft 206 is a stepped shaft of Φ25Ⅹ300mm. Although it is relatively heavy, as the output shaft of the human-powered engine, it has strong mechanical strength and will not bend, deform or wear. The outer diameter at both ends of the central shaft is Φ16mm. Two groups of platforms with opposite directions are milled at both ends of the central shaft 206, and the right crank sprocket and the left crank are fixed by positioning pins. A 48-tooth large sprocket is selected, and the center distance of the crank is 165mm. It has good quality and low cost. The central shaft 206, the U-shaped brake handle two 814 and the U-shaped brake handle one 804 installed at the front end of the main beam assembly 200 have a compact structure, make full use of the space in front of the middle joint of the whole vehicle, and have an anti-collision protection effect on the front fork. The gap between the outer surface of the contact brake and the outer tire of the front wheel is not more than 20mm.

[0040] The above is the overall working process of the present invention. Just repeat this step when using it next time.

[0041] It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0042] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

[0043] The above description of the present invention and its embodiments is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. In general, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, design similar structural modes and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. A double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive trailer-type bicycle, characterized in that: The complete bicycle (000) consists of components such as the bicycle main body (100), the frame assembly (200), the gearbox (300), the motor (400), the rear axle assembly (500), the rear wheel assembly (600), the rear saddle (700), the band brake (800), the battery (900), and other accessories and fasteners. The frame assembly (200) is fixed to the connection between the middle joint of the bicycle main body (100) and the seat stay and the frame by hexagon long bolts. The gearbox (300) is installed below the bicycle main body (100). The motor (400) is installed between the gearbox (300) and the rear axle assembly (500). The motor (400) is fixed by inserting the shaft extensions on both sides into the special-shaped holes of the left rear beam (201) and the right rear beam (202). The rear axle assembly (500) is provided with a brake drum assembly and a freewheel assembly. A touch brake is provided at the front of the frame. A brake handle is provided in front of the bicycle main body (100) for braking the brake drum on the rear axle assembly (500).

2. The double-rear-wheel, double-person, double-drive, double-brake, gear-shifting and interactive towable bicycle according to claim 1, characterized in that: The frame assembly (200) consists of components such as the left rear beam (201), the right rear beam (202), the end plate (203), the bracket (204), etc. and fastening components, forming a semi-closed rectangular frame. Both the left rear beam (201) and the right rear beam (202) are provided with blanking and punching with opposite flanging directions. Accessories such as warning lighting fixtures and vehicle license plates can be installed at the tail of the frame assembly (200).

3. A double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, towable bicycle according to claim 1, characterized in that: A small sprocket II (012) is installed on the gearbox (300). A bearing seat (208) and a central shaft (206) are installed on the frame assembly (200). A large sprocket assembly (011) with a crank pedal is installed on the right side of the central shaft (206). The gearbox (300) is provided with a small sprocket II (012) and a chain (013). The small sprocket II (012) and the chain (013) form a sprocket-chain transmission pair. A large sprocket II (014) is installed on the output shaft of the gearbox (300). The large sprocket II (014) and a large sprocket I (505) installed on the rear axle assembly (500) form a forward sprocket-chain transmission pair through a chain (015). A middle chain (016) is installed on the output shaft on the right side of the gearbox (300). The chain (017) on the gearbox (300) and the large sprocket I (505) form a reverse sprocket-chain transmission pair.

4. A double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, towable bicycle according to claim 1, characterized in that: The motor (400) is installed in the middle of the frame assembly (200), between the gearbox (300) and the rear axle (501). An electric switch knob (404) is provided on the motor (400). Both ends of the rear axle (501) are inserted into the special-shaped holes of the left and right rear beams and fixed by nuts. The end of the rear axle (501) with a wire is located on the right rear beam (202).

5. A double-rear-wheel, double-person, double-drive, double-brake, gear-variable, interactive, trailer-type bicycle according to claim 1, characterized in that: The rear axle (501) is installed at the rear D holes of the left rear beam (201) and the right rear beam (202), and is fixed by a hexagon bolt assembly I. A drum assembly (503) is installed on the rear axle (501). The drum assembly (503) includes a brake drum (504) and a large sprocket I (505). Two groups of flywheels I (507) are screwed and installed on the rear axle (501) through a threaded sleeve (506). A spacer sleeve (508) and a washer (509) are arranged on the rear axle (501) for axial limit. A flat key I (521) and a flat key II (522) arranged on the rear axle (501) are used for circumferential positioning. Two groups of the rear wheel assemblies (600) are installed on the two side shaft extensions of the rear axle (501) and are fixed by nuts. A bearing (502) is arranged on the rear axle (501). A set screw is arranged on the inner ring of the bearing (502). The outer ring of the bearing (502) is used for installing a bearing seat (208) through a clamping plate (510) with a threaded hole.

6. A double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, trailer-type bicycle according to claim 1, characterized in that: The rear wheel assembly (600) includes a hub tube, a chrome-plated steel rim (605), wire spokes (606), a connecting nut (607), an outer tire (608) and an inner tube (609). A flywheel II (602) is installed on the outer side of the hub tube, and a flywheel III (604) is installed on the inner side of the hub tube.

7. A double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, trailer-type bicycle according to claim 1, characterized in that: The main beam assembly (200) is additionally provided with a front saddle (701). A steel pipe (702) is arranged below the front saddle (701). Threads are arranged above the steel pipe (702). The height of the front saddle (701) can be adjusted by a lock nut (704) for the steel pipe (702). A platform is milled at the lower end of the steel pipe (702), and circumferential positioning of the steel pipe (702) is achieved through a pressing plate (706), so that the front saddle (701) cannot rotate randomly. A spring shock-absorbing assembly and a compression spring (703) are arranged inside the front saddle (701) to form a double shock-absorbing device. A bracket (204) is installed at the tail of the main beam assembly (200). The bracket (204), the left rear beam (201) and the right rear beam (202) are connected to the rear vehicle through a hexagon bolt assembly II (721). The pressing plate (706) is fixed through a screw assembly (722). The steel pipe (702) is locked through a split pin (723).

8. A double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, towed bicycle according to claim 1, characterized in that: The brake system includes components such as a brake drum (504), a leather strap (801), a leather sheath (802), a connecting rod (803), a U-shaped brake lever one (804), a handle one (805), a pressure plate (806), and a return spring (807). The U-shaped brake lever one (804) is located at the front end of the beam assembly (200) and straddles both sides of the front tube of the frame. The fulcrum is set on the connecting rod (803) to form a lever system. When the handle one (805) is pulled backward, the leather strap (801) can be tightened to wrap around the brake drum (504), braking the rear axle (501) and two groups of rear wheel assemblies (600). One end of the return spring (807) is fixedly connected to the flanging of the end plate (203), and the pin shaft (808) of the U-shaped brake lever one (804) plays a limiting role.

9. A double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, trailer-type bicycle according to claim 1, characterized in that: The U-shaped lever two (814) is located at the very front end of the beam assembly (200) and straddles both sides of the front tube of the frame. The fulcrum K is located on the connecting rod (803) to form a lever system. When the handle two (815) is pushed, the contact brake (810) can be pushed forward, and when it touches the outer tire of the front wheel, it can play a braking role. The other end of the return spring (807) is fixed on the connecting rod (803) at the fulcrum L of the U-shaped brake lever one (804).

10. A double-rear-wheel, double-person, double-drive, double-brake, gear-shifting, interactive, trailer-type bicycle according to claim 1, characterized in that: A central shaft (206) is installed at the C hole at the front end of the beam assembly (200). The bearing seat (208) is fixed on the left rear beam (201) and the right rear beam (202) through the hexagon bolt assembly three (221). Two groups of platforms with opposite directions are milled at both ends of the central shaft (206), and the right crank sprocket and the left crank are fixed through a positioning pin. The central shaft (206), the U-shaped lever two (814), and the U-shaped brake lever one (804) installed at the front end of the beam assembly (200) have an anti-collision effect on the front fork.

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