CN112758235A

CN112758235A - Method for modifying anti-falling device formed by modifying middle support

Info

Publication number: CN112758235A
Application number: CN202110133079.5A
Authority: CN
Inventors: 刘淑林
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-02-01
Filing date: 2021-02-01
Publication date: 2021-05-07

Abstract

A method for modifying a falling-down prevention device formed by modifying a middle support comprises the first step of manufacturing a shared rear wheel brake handle, and additionally arranging a traction arm and another section of drum head positioning plate; secondly, a fixing frame is additionally arranged below a bottom beam of the electric vehicle; thirdly, a traction wire is arranged on the electric vehicle; fourthly, modifying the middle support, and additionally arranging a caster, a damper and a through hole under the tie; fifthly, connecting the traction line with the two bottom legs of the middle support into a whole through a triangular rope; the traction line and the middle support are connected and then form a linkage mechanism with the shared rear wheel brake handle, when the rear wheel brakes suddenly, the shared rear wheel brake handle drives the traction arm to rotate downwards through the traction line and the triangular rope, the support tilts downwards, the two casters arranged below the middle support are synchronously grounded due to the downward tilting of the middle support, and the two grounded casters play a role in supporting the balance of the vehicle body during sudden braking.

Description

Method for modifying anti-falling device formed by modifying middle support

Technical Field

A method for modifying a falling-down prevention device formed by modifying a middle support belongs to the technical field of matching of technical improvement of two-wheeled electric vehicles and motorcycles.

Background

The electric bicycle is an individual household engaged in electric bicycle and motorcycle repair work for many years, and the electric bicycle and the motorcycle with two wheels are frequently ridden at ordinary times; the phenomenon that the rear wheel can slide transversely to cause the left and right swinging of a vehicle body is easy to occur if the rear wheel brakes suddenly (because the front wheel can not brake at the moment, a greater accident that the vehicle turns over is easily caused) after the running speed of the existing two-wheel electric vehicle and motorcycle exceeds 25 kilometers is found, and the swinging phenomenon of the twisted hip of the vehicle body is more serious if the vehicle speed is higher, so that the accident potential that the vehicle is easy to fall down is brought to normal riding trip; particularly, accidents of falling injury are frequent for small brows which are delivered for taking out; in view of the above, i think that the technical means are needed to overcome the defects, so as to generate innovative inspiration (motivation), and particularly propose a method for modifying a falling prevention device modified from a middle support.

Disclosure of Invention

The invention aims to provide a method for modifying a falling-down prevention device modified from a middle support, so that the accident potential caused by easy falling down of two-wheeled electric vehicles and motorcycles in the prior art during emergency braking is eliminated;

the first step of the modification is to manufacture a shared rear wheel brake handle, the shared rear wheel brake handle is modified from the used rear wheel brake handle (the shared brake handle is called because the rear wheel brake handle has two functions), and the technical means adopted by the modification of the shared rear wheel brake handle is as follows: the outside of the rear wheel brake handle is connected with a section of traction arm (namely a rocker arm), the traction arm is made of a steel plate, the traction arm and the rear wheel brake handle made of steel are welded and connected into a whole, and the welded traction arm and the rear wheel brake handle are on the same plane; the outer end (the side close to the handlebar is the inner) of the traction arm is provided with a clamping groove connected with the end head of the cord of the brake cable, and the clamping groove is structurally used for connecting the traction arm with one end of a joint of the cord in another traction cable; the length of the modified traction arm can meet the requirement that two trundles in a support during traction land when a rear wheel emergency brake is operated (when a brake handle is pinched), so that the swinging phenomenon of the twisting hip of a vehicle body caused by the rear wheel emergency brake of the electric vehicle is overcome;

another section of drum head positioning plate is connected to the drum head positioning plate which is used for fixing one end of the drum head of the rear wheel brake cable, and the other section of drum head positioning plate is formed by cutting (removing the annular sleeve part fixed on the handlebar, and increasing the length if the length is not enough) the drum head positioning plate; the other section of drum head positioning plate is connected with the existing drum head positioning plate for fixing one end of the rear wheel brake line drum head into a whole in a welding way; the length of the other section of drum head positioning plate after welding is matched with the length of a traction arm (rocker arm), and the other section of drum head positioning plate is used for fixing one end of a drum head of another traction wire; thus, the remanufacturing characteristic of the brake handle on the handlebar is formed, namely the remanufacturing process on the handlebar is finished;

the second step of the modification is: the body of the electric vehicle is reformed, a fixed mount is additionally arranged below a bottom beam of the electric vehicle, the fixed mount is reformed by adopting a lower fixed positioning plate in a rear wheel brake in the prior art, the plate body of the reformed fixed mount is made into a right trapezoid, and the fixed mount and a middle girder of the body are vertically welded and connected into a whole; the modified fixed frame is used for installing and fixing the lower end of an additional traction line; thus, the related remanufacturing characteristics of the body of the electric vehicle are formed, namely, the remanufacturing part related to the body is finished;

the third step of the modification is: another traction line is arranged on the electric vehicle: the brake cable that a pull wire that establishes in addition chose this car supporting to use (the brake cable all can supply to use after the transformation of front and back, as long as length is enough long enough), and the installation method is: the traction line is laid on the vehicle body along a section of path of the rear wheel brake line, and the drum heads (with different drum head shapes) of the outer leather tubes at two ends of the traction line are respectively connected with the other drum head positioning plate and the fixing frame into a whole; two ends of a cord in the outer sheath tube of the traction wire are respectively fixedly connected with the clamping groove in the traction arm and the middle part of the triangular rope into a whole; thus, a remanufacturing feature of an additional pull wire is formed; namely the installation operation of the other traction line is finished;

the fourth step of the modification is: the middle support matched with the vehicle is reformed: the modified place has two places, one is to modify the bottom end of the middle support, cut off a section of the bottom of each of the two bottom legs of the middle support (only one caster is shown in the figure for comparison), mount a caster under the cut end face, respectively weld the caster frame of the caster and the bottom of the two bottom legs of the middle support to be connected into a whole; the length of the two bottom legs of the middle support after the caster is welded is equal to the length of the bottom legs before the caster is not cut off; therefore, the original use function of the middle support is ensured to be unchanged;

the inner sides of the two caster frames are respectively connected with a damper, one end of the wheel shaft of the caster is inserted into the shaft hole of the damper and then connected into a whole, and the shell of the damper and the caster frames are fixedly connected into a whole; so that the caster wheel and the damper are installed and connected into a whole; the mounted damper is used for controlling the flexible rotation of the caster and making resistance for the rotation of the caster; therefore, the phenomenon that the caster wheels slide due to uneven terrain when the middle support is used for supporting the vehicle body and parking is prevented; when the caster brakes and lands, the friction resistance with the ground is generated, and the caster maintains the balance of the vehicle body when braking and also helps to improve the braking effect of the brake; therefore, the damper on the caster has double functions of parking and braking the electric vehicle;

secondly, another part of two bottom legs of the middle support is reformed: the technical means adopted by the remanufacturing is as follows: two bottom legs of the middle support are symmetrically drilled with a through hole respectively, and the through holes are positioned above the middle position of the length of the bottom legs; the through hole is used for penetrating the triangular rope and realizing the connection with a cord of another traction line; therefore, the structural characteristics of the caster, the damper and the through hole are added in the modified middle support, and the modification of the middle support is finished;

the fifth step of the modification is: the other set traction line is connected with the middle support in a connecting mode by adopting the following technical means: an additional traction line is connected with the two bottom legs of the middle support into a whole through a triangular rope; the triangular rope is made of a section of brake cable, the middle part of the triangular rope and the bottom end of another traction cable (namely, an inner rope arranged in a pipe skin of the brake cable) are tied and connected into a whole, and then the two ends of the triangular rope are respectively inserted into through holes on two bottom legs of the middle support, so that a three-point structure (so called triangular rope) is formed; the penetrated triangular rope can be flexibly drawn back and forth in the through hole; the reserved length (namely the movable forming) of the triangular rope is determined according to the vertical to horizontal movable stroke of the middle support, the two ends of the triangular rope are tensioned when the middle support is in a horizontal state, the rope in an additional traction line is pulled outwards to extend out for a section, and the length of the extended section is just the stroke length (the shared rear wheel brake handle is in a non-braking state) which can drive the support to incline downwards to cause the two caster wheels to be grounded when the rear wheel is operated to brake; then, two ends of the triangular rope are sealed by seal heads (line hammers) so as to ensure that the middle support is not influenced by another traction line when in a supporting state; thus, an additional traction wire and a middle support linkage structure are arranged;

through the five technical modifications, the electric vehicle structurally forms a new structural characteristic formed by matching and connecting a common rear wheel brake handle, an additionally arranged traction line, a newly-added fixed frame of the traction line and the modified middle support;

the function process of the newly added structural features is as follows: when the emergency brake of the rear wheel is carried out during the running of the vehicle, the shared rear wheel brake handle drives the traction arm (rocker arm) to rotate for an angle, the rotation of the traction arm pulls out a cord in an additionally arranged traction line for a certain distance, the other end (lower end) of the cord is pulled by the triangular cord to support downwards to rotate and form inclination (namely the middle support is inclined downwards from a flat state), the two casters are synchronously grounded due to the downward inclination of the middle support, and the two grounded casters play a role in supporting the balance of the vehicle body during the emergency brake;

when the brake of the rear wheel is released, the shared rear wheel brake handle is loosened, the inclined middle support is reset to the original flat state under the action of the tension of the spring of the middle support, and the shared rear wheel brake handle is used for finishing the protection action process during one emergency brake of the rear wheel;

when the middle support needs to be supported during parking, the triangular rope can flexibly slide in the through hole, and the triangular rope is in a tensioning state only when the middle support is in a flat state, so that the normal parking support using of the middle support is not influenced; this is the use of the present application;

the beneficial technological effect of this application is: the improved structure makes full use of the rear wheel brake handle used on the vehicle, and the linked structural characteristic is formed by the additionally arranged traction wire and the middle support, so that two trundles in the middle support can be driven to be synchronously grounded during emergency braking of the rear wheel, and the synchronous action of emergency braking of the rear wheel of the electric vehicle and the grounding of the trundles in the middle support is realized; the linkage structure is characterized in that the unstable phenomenon of vehicle body left-right swing caused by transverse slipping of the rear wheel during emergency braking of the electric vehicle is fundamentally eliminated; through the above-mentioned remanufacturing means (i.e. the remanufacturing technology) for the electric vehicle in the prior art, new structural characteristics and new function of the electric vehicle are increased, so that the manufacturing technology (characteristics) and the service performance of the electric vehicle are more perfect.

Drawings

In the drawings:

FIG. 1 is a front view of a fall arrest device modified from a mid-support;

FIG. 2 is a front view of the modified mid-support;

fig. 3 is a front view of the modified rear wheel brake handle.

Description of reference numerals:

in the figure, 1, a middle support; 2. a rear wheel brake handle is shared; 3. a pull wire; 4. a fixed mount; 5. a rear wheel brake handle is used; 6. a traction arm; 7. a clamping groove; 8. a caster wheel; 9. another drum head positioning plate; 10. a drum head; 11. sealing the end; 12. a triangular rope; 13. a bottom leg; 14. a caster frame; 15. a damper; 16. a through hole; 17. a thread rope.

Detailed Description

As shown in fig. 1, 2 and 3, a method for modifying a fall-down prevention device modified from a middle support 1 is provided, so that the accident potential of easy fall-down caused by sudden braking of a two-wheeled electric vehicle and a motorcycle in the prior art is eliminated;

the first step of the modification is to manufacture a shared rear wheel brake handle 2, the shared rear wheel brake handle 2 is modified from a used rear wheel brake handle 5 (the shared rear wheel brake handle is called as a shared brake handle because the rear wheel brake handle has two functions), and the technical means adopted by the modification of the shared rear wheel brake handle 2 is as follows: a section of traction arm (namely a rocker arm) 6 is connected to the outer side of the rear wheel brake handle 5, the traction arm 6 is made of a steel plate, the traction arm 6 and the rear wheel brake handle 5 made of steel are welded and connected into a whole, and the welded traction arm 6 and the rear wheel brake handle 5 are on the same plane; a clamping groove 7 connected with the end of a cord 17 of a brake cable is manufactured at the outer end (the side close to a handlebar is inner) of the traction arm 6, and the structure of the clamping groove 7 (note: the structure of the clamping groove is the clamping groove structure in the prior art) is used for connecting the traction arm 6 with one end of a joint of the cord 17 in another traction cable 3; the length of the modified traction arm (namely the rocker arm) 6 can meet the requirement that two trundles 8 in the support 1 are grounded during traction when a rear wheel emergency brake is operated (when a brake handle is pinched), so that the swinging phenomenon of the twisted buttocks of a vehicle body caused by the electric vehicle at the rear wheel emergency brake is overcome;

another drum head positioning plate 9 is connected to the drum head positioning plate for fixing one end of the drum head of the rear wheel brake cable, and the drum head positioning plate 9 is formed by cutting the drum head positioning plate (removing the annular sleeve part fixed on the handlebar, and increasing the length if not enough); the other section of drum head positioning plate 9 is connected with the existing drum head positioning plate for fixing one end of the rear wheel brake line drum head into a whole by welding; the length of the other section of drum head positioning plate 9 after welding is matched with the length of the traction arm (rocker arm) 6, and the other section of drum head positioning plate 9 is used for fixing a drum head 10 at one end of another traction wire 3; thus, the remanufacturing characteristic of the brake handle on the handlebar is formed, namely the remanufacturing process on the handlebar is finished;

the second step of the modification is: modifying the body of the electric vehicle: a fixing frame 4 is additionally arranged below a bottom beam of the electric vehicle, the fixing frame 4 is formed by modifying a lower fixing positioning plate in a rear wheel brake in the prior art, a plate body of the modified fixing frame 4 is made into a right-angled trapezoid, and the fixing frame 4 and a middle girder of a vehicle body are vertically welded and connected into a whole; the modified fixed frame 4 is used for installing and fixing the lower end of another traction wire 3; thus, the related remanufacturing characteristics of the body of the electric vehicle are formed, namely, the remanufacturing part related to the body is finished;

the third step of the modification is: another traction wire 3 is installed on the electric vehicle: the brake cable that a pull wire 3 that establishes in addition chose this car supporting to use (the brake cable all can supply to use after the transformation of front and back, as long as length is enough long enough), and the installation method is: the traction line 3 is laid on the vehicle body along a section of path of the rear wheel brake line, and the drum heads (with different drum head shapes) of the outer leather tubes at two ends of the traction line 3 are respectively connected with the other drum head positioning plate 9 and the fixing frame 4 into a whole; two ends of a cord 17 in the outer skin tube of the traction wire 3 are respectively fixedly connected with the clamping groove 7 in the traction arm 6 and the middle part of the triangular rope 12 into a whole; in this way, a modified feature of an additional traction wire 3 is formed; namely, the installation operation of the other traction wire 3 is finished;

the fourth step of the modification is: the middle support matched with the vehicle is reformed: the modified places are two places, one is the modification of the bottom end of the middle support 1, the bottoms of the two bottom legs 13 of the middle support 1 are respectively cut off (only one caster is shown in the figure for comparison), the casters 8 are respectively installed below the cut-off end surfaces, and the caster frame 14 of each caster 8 and the bottoms of the two bottom legs 13 of the middle support 1 are respectively welded and connected into a whole; the length of the two bottom legs 13 of the middle support 1 after welding the caster 8 is equal to the length of the bottom legs before truncation; thus ensuring the original use function of the middle support 1 to be unchanged;

the casters 8 are respectively arranged below the two bottom legs 13 of the middle support 1, the casters with a wheel shaft type structure (namely, the casters with wheels and shafts fixed into a whole and the casters with wheel shafts capable of integrally rotating in the shaft holes of the caster frames) are selected, the inner sides of the two caster frames 14 are respectively connected with a damper 15, one end of the wheel shaft of each caster 8 is inserted into the shaft hole of the damper 15 and then connected into a whole, and the shell of each damper 15 and the caster frame 14 are fixedly connected into a whole; so that the caster 8 and the damper 15 are installed and connected into a whole; the mounted damper 15 is used for controlling the flexible rotation of the caster 8 and making resistance for the rotation of the caster 8; therefore, the phenomenon that the caster 8 slides due to uneven terrain when the middle support 1 supports the vehicle body and parks is prevented; when the caster 8 is braked and lands, the friction resistance with the ground is generated, and the caster 8 helps to improve the braking effect of the brake while maintaining the balance of the vehicle body when braking; therefore, the damper 15 on the caster has double functions of parking and braking the electric vehicle;

secondly, two bottom legs 13 of the middle support 1 are modified: the adopted technical means is as follows: a through hole 16 is symmetrically drilled on each of the two bottom legs 13 of the middle support 1, and the through hole 16 is positioned above the middle position of the length of each bottom leg 13; the through hole 16 is used for penetrating the triangular rope 12 and realizing connection with a rope 17 of another traction line 3; thus, the structural characteristics of the caster 8, the damper 15 and the through hole 16 are newly added in the modified middle support 1, and the modification of the middle support 1 is completed;

the fifth step of the modification is: the other traction wire 3 is connected with the middle support 1, and the connection mode adopts the following technical means: an additional traction line 3 is connected with two bottom legs 13 of the middle support 1 into a whole through a triangular rope 12; the triangular rope 12 is made of a cord 17 of a section of brake cable, the middle part of the triangular rope 12 and the bottom end of the cord 17 (namely, an inner cord arranged in a tube skin of the brake cable) in another traction line 3 are tied and connected into a whole, and then the two ends of the triangular rope 12 are respectively inserted into through holes 16 on two bottom legs 13 of the middle support 1, so that a three-point structure (so called triangular rope) is formed; the penetrated triangular rope 12 can be flexibly drawn back and forth in the through hole 16; the reserved length (namely the movable forming) of the triangular rope 12 is determined according to the movable stroke of the middle support 1 from the vertical position to the horizontal position, the two ends of the triangular rope 12 are tensioned when the middle support 1 is in the horizontal position, the rope 17 of the other traction line 3 is pulled outwards to extend out for a section, and the length of the extended section is just the stroke length which can drive the middle support 1 to incline downwards to cause the two caster wheels 8 to be grounded when the rear wheel brake is operated; then, two ends of the triangular rope 12 are sealed by a seal head (a plumb bob) 11, so that the middle support 1 is not influenced by another traction wire 3 when being supported; thus, an additional traction wire 3 and a linkage structure of the middle support 1 are arranged;

through the five technical modifications, the electric vehicle structurally forms a new structural characteristic formed by matching and connecting a common rear wheel brake handle 2, an additionally arranged traction wire 3, a newly added fixing frame 4 of the traction wire 3 and the modified middle support 1;

the action process of the newly added structure is as follows: when the emergency brake of the rear wheel is carried out during the running of the vehicle, the shared rear wheel brake handle 2 drives the traction arm (rocker arm) 6 to rotate for an angle, the rotation of the traction arm (rocker arm) 6 pulls out a cord 17 in an additionally arranged traction line 3 for a certain distance, the other end (lower end) of the cord 17 is pulled by the triangular rope 12 to pull the middle support 1 to rotate downwards to form an inclination, the downward inclination of the middle support 1 enables the two caster wheels 8 to be synchronously grounded, and the two grounded caster wheels 8 play a role in supporting the balance during the emergency brake of the vehicle body;

when the brake of the rear wheel is released, the shared rear wheel brake handle 2 is loosened, the inclined middle support 1 is reset to the original flat state under the action of the tension of the spring of the middle support, and the shared rear wheel brake handle 2 finishes the protection action process during one emergency brake of the rear wheel;

when the middle support 1 needs to be supported during parking, the triangular rope 12 can flexibly slide in the through hole 16, and the triangular rope 12 is in a tensioned state only when the middle support 1 is in a flat state, so that the normal parking supporting use of the middle support 1 is not influenced; this is the use of the present application;

the beneficial technological effect of this application is: the improved structure fully utilizes the characteristic of a linkage structure formed by a rear wheel brake handle 5 used on the vehicle and the middle support 1 through an additionally arranged traction wire 3, and drives two trundles 8 in the middle support 1 to be synchronously grounded when the rear wheel is suddenly braked, so that the synchronous action of the sudden braking of the rear wheel of the electric vehicle and the grounding of the trundles 8 in the middle support 1 is realized, and the characteristic of the linkage structure fundamentally eliminates the unstable phenomenon of left-right swinging of the vehicle body caused by transverse slipping of the rear wheel when the sudden braking is carried out; through the technical improvement of the electric vehicle in the prior art, the novel structural characteristics and the novel function of the electric vehicle are increased, so that the structural characteristics and the service performance of the electric vehicle are more perfect.

Claims

1. The method for modifying the anti-falling device modified from the middle support is provided, so that the accident potential caused by the fact that the two-wheeled electric vehicle and the motorcycle in the prior art are easy to fall when the two-wheeled electric vehicle and the motorcycle are braked suddenly is eliminated; the method is characterized in that:

the first step of the modification is to manufacture a shared rear wheel brake handle (2), the shared rear wheel brake handle (2) is modified by a rear wheel brake handle (5) which is used, and the technical means adopted by the modification of the shared rear wheel brake handle (2) is as follows: a section of traction arm (6) is connected to the outer side of the rear wheel brake handle (5), the traction arm (6) is made of steel plates, the traction arm (6) and the rear wheel brake handle (5) made of steel are welded and connected into a whole, and the welded traction arm (6) and the rear wheel brake handle (5) are on the same plane; the outer end of the traction arm (6) is provided with a clamping groove (7) connected with the end of a cord (17) of a brake cable, and the clamping groove (7) is structurally used for connecting the traction arm (6) with one end of a joint of the cord (17) in another traction cable (3) for use; the length of the modified towing arm (6) can meet the requirement that two caster wheels (8) in the support (1) land during towing when the rear wheel emergency brake is operated, so that the swinging phenomenon of the hip of the vehicle body caused by the rear wheel emergency brake of the electric vehicle is overcome;

another section of drum head positioning plate (9) is connected to the drum head positioning plate for fixing one end of the drum head of the rear wheel brake cable, and the other section of drum head positioning plate (9) is formed by cutting and modifying the drum head positioning plate; the other section of drum head positioning plate (9) is welded and connected with the existing drum head positioning plate for fixing one end of the rear wheel brake line drum head into a whole; the length of the other section of drum head positioning plate (9) after welding is matched with the length of the traction arm (6), and the other section of drum head positioning plate (9) is used for fixing one end drum head (10) of another traction wire (3) for use; thus, the remanufacturing characteristic of the brake handle on the handlebar is formed, namely, the remanufacturing operation process on the handlebar is finished;

the second step of the modification is: modifying the body of the electric vehicle: a fixing frame (4) is additionally arranged below a bottom beam of the electric vehicle, the fixing frame (4) is formed by modifying a lower fixing positioning plate in a rear wheel brake in the prior art, a plate body of the modified fixing frame (4) is made into a right-angled trapezoid, and the fixing frame (4) and a middle girder of a vehicle body are vertically welded and connected into a whole; the modified fixing frame (4) is used for installing and fixing the lower end of another traction wire (3); thus, the related remanufacturing characteristics of the body of the electric vehicle are formed, namely, the remanufacturing part related to the body is finished;

the third step of the modification is: another traction line (3) is arranged on the electric vehicle: the additionally arranged traction line (3) is a brake line matched with the vehicle for use, and the installation method comprises the following steps: the traction line (3) is laid on the vehicle body along a section of path of the rear wheel brake line, and the drum heads of the outer leather tubes at the two ends of the traction line (3) are respectively connected with the other drum head positioning plate (9) and the fixing frame (4) into a whole; two ends of a cord (17) in the outer skin tube of the traction wire (3) are respectively fixedly connected with the clamping groove (7) in the traction arm (6) and the middle part of the triangular rope (12) into a whole; in this way, a modified characteristic of a further traction wire (3) is formed; namely the installation operation of the other traction wire (3) is finished;

the fourth step of the modification is: the middle support (1) matched with the vehicle is reformed: the modified place has two places, one is the modification of the bottom end of the middle support (1), the bottoms of two bottom legs (13) of the middle support (1) are respectively cut off, the caster wheels (8) are respectively arranged below the cut-off end surfaces, and the caster frames (14) of the caster wheels (8) and the bottoms of the two bottom legs (13) of the middle support (1) are respectively welded and connected into a whole; the length of the two bottom legs (13) of the middle support (1) after the caster (8) is welded is equal to the length of the bottom legs before the caster is cut off; thus ensuring the original use function of the middle support (1) to be unchanged;

the lower surfaces of two bottom legs (13) of the middle support (1) are respectively provided with a caster (8), the casters (8) adopt caster wheels with wheel shaft type structures, the inner sides of two caster frames (14) are respectively connected with a damper (15), one end of a wheel shaft of each caster (8) is inserted into a shaft hole of the damper (15) and then is connected into a whole, and a shell of the damper (15) and the caster frames (14) are fixedly connected into a whole; so that the caster wheel (8) and the damper (15) are installed and connected into a whole; the mounted damper (15) is used for controlling the flexible rotation of the caster (8) and making resistance for the rotation of the caster (8); therefore, the phenomenon that the caster (8) slides due to uneven terrain when the middle support (1) supports the vehicle body to park is prevented; when the caster wheel (8) is braked and landed, the friction resistance with the ground is generated, and the caster wheel (8) helps to improve the braking effect of the brake while maintaining the balance of the vehicle body when the brake is performed; therefore, the damper (15) on the caster has double functions of parking and braking the electric vehicle;

secondly, two bottom legs (13) of the middle support (1) are reformed: the adopted technical means is as follows: two bottom legs (13) of the middle support (1) are symmetrically drilled with a through hole (16), and the through hole (16) is positioned above the middle position of the length of the bottom legs (13); the through hole (16) is used for penetrating the triangular rope (12) and realizing connection with a rope (17) of another traction line (3); therefore, the structural characteristics of the caster (8), the damper (15) and the through hole (16) are newly added in the modified middle support (1), and the modification of the middle support (1) is completed;

the fifth step of the modification is: the other traction wire (3) is connected with the middle support (1) in a connecting mode by adopting the following technical means: an additional traction line (3) is connected with the two bottom legs (13) of the middle support (1) into a whole through a triangular rope (12); the triangular rope (12) is made of a cord (17) of a section of brake cable, the middle part of the triangular rope (12) and the bottom end of the cord (17) in another traction line (3) are tied and connected into a whole, and then the two ends of the triangular rope (12) are respectively inserted into through holes (16) on two bottom legs (13) of the middle support (1), so that a three-point structure is formed; the penetrated triangular rope (12) can be flexibly drawn back and forth in the through hole (16); the reserved length of the triangular rope (12) is determined according to the moving stroke of the middle support (1) from vertical to horizontal, when the middle support (1) is in a horizontal state, two ends of the triangular rope (12) are tensioned, at the moment, a rope (17) of an additional traction line (3) is pulled outwards to extend out for a section, and the length of the extended section is just the stroke length which can drive the middle support (1) to incline downwards to enable two trundles (8) to be grounded when a rear wheel brake is operated; then, two ends of the triangular rope (12) are sealed by using end sockets (11), so that the middle support (1) is not influenced by another traction wire (3) when in a supporting state; thus, an additional traction wire (3) and a linkage structure of the middle support 91 are arranged;

through the five technical modifications, the electric vehicle structurally forms a new structural characteristic formed by matching and connecting a common rear wheel brake handle (2), an additional traction wire 93, a newly-added fixing frame (4) of the traction wire (3) and the modified middle support (1);

the action process of the newly added structure is as follows: when the emergency brake of the rear wheel is carried out during the running of the vehicle, the common rear wheel brake handle (2) drives the traction arm (6) to rotate for an angle, the rotation of the traction arm (6) pulls out a cord (17) in an additionally arranged traction line (3) for a certain distance, the other end of the cord (17) pulls the middle support (1) to rotate downwards through the triangular rope (12) to form an inclination, the downward inclination of the middle support (1) enables the two casters (8) to be synchronously grounded, and the two grounded casters (8) play a role in supporting the balance of the vehicle body during the emergency brake;

when the brake of the rear wheel is released, the shared rear wheel brake handle (2) is loosened, the inclined middle support (1) is reset to the original flat state under the action of the tension of the spring of the middle support, and the shared rear wheel brake handle (2) completes the protection action process during one emergency brake of the rear wheel;

when the middle support (1) needs to be supported during parking, the triangular rope (12) can flexibly slide in the through hole (16), and the triangular rope (12) is in a tensioning state only when the middle support (1) is in a flat state, so that the normal parking supporting use of the middle support (1) is not influenced; this is the use of the present application.