CN206871288U - A kind of novel labour saving lever driven bicycle - Google Patents

Abstract

The utility model discloses a kind of novel labour saving lever driven bicycle, including handlebar, fore-stock, front fork, front vehicle wheel, preceding slash, rear slash, whippletree, back vent, rear wheel and power drive system.It is characterized in, power drive system includes main lever, fixed plate, pedal, crank, flywheel, preceding fluted disc, rear tooth disk, chain and the mechanism for reducing main lever amplitude of fluctuation, the mechanism for reducing main lever amplitude of fluctuation includes the first lever, the second lever, the 3rd lever, the 4th lever and the 5th lever, and the crank is provided with mobile jib, rotating shaft hack lever and power rail.On the basis of the utility model reduces the long power arm of mechanism bicycle holding of main lever amplitude of fluctuation by designing, pedal and ground contact are avoided.And by designing the crank with flywheel, using the inertia and knockout press of flywheel, reach further labour-saving effect, and compared to existing bicycle or electric car significant effect, without charging, achievable long range is ridden, and saves energy environmental protection again.

Description

A kind of novel labour saving lever driven bicycle

Technical field

It the utility model is related to a kind of bicycle, more particularly to a kind of novel labour saving lever driven bicycle.

Background technology

Since the Third Plenary Session of the 11th Central Committee of the Chinese Communist Party, bicycle production in China's is growing with the development of production in light industry, promotes The scientific research of bicycle, no matter University Scientific Research mechanism, incorporated business or individual, all improvement to bicycle and development make Huge contribution is gone out.Now widely used bicycle is to pedal what power drove on pedal by acting on, in driving axis On fix a chain sprocket, by chain sprocket, chain-driving rear tooth disk rotate, realize rear car two-wheel driving bicycle advance.It is this The kind of drive, which is trampled, once needs an annular great circle, could complete one and trample the cycle.With the change of the pedal anglec of rotation Change, driving torque is also changing, and during annular great circle, annular distance 70% is all to flog a dead horse, and consumes people's in vain Muscle power and time.Therefore all the time, people are devoted to improve energy utilization by transforming bicycle drive mechanism Rate, manufacture laborsaving, comfortable bicycle of riding.But based on current document apparently, or labour-saving bicycle be structure excessively Complexity, manufacturing cost is too high, otherwise labor-saving effect unobvious, do not reach the requirement of comfort level of riding.

Lever bicycle has abandoned chain, sprocket wheel, and then cut axis, chain cover using leverage driving bicycle Etc. associated component；Because its lever length is 3~5 times of former length of kicking one's legs, labor-saving effect is very notable.It is but existing Lever bicycle face one it is great the problem of：Treadle of driving a vehicle is grown, and power arm is longer, laborsaving, but treadle amplitude of fluctuation is very Greatly, treadle end is easy to touch with ground when reaching obvious laborsaving degree, and often pedals a treadle, and the angle that flywheel turns over is very It is small, therefore bicycle pace is very low, can not come into operation.This technological deficiency of the prior art is also to be applied the National People's Congress Amount experiment is confirmed.

Utility model content

Based on above-mentioned technical problem, the utility model provides a kind of novel labour saving lever driven bicycle, passes through lever The design of mechanism, solves the small technical problem of treadle amplitude of fluctuation in the prior art is big, flywheel turns over angle, in labour-saving Meanwhile treadle height is moderate, meet the needs in bicycle actual use.

To achieve the above object, the specific technical scheme of the utility model is：A kind of novel labour saving lever driven bicycle, Including handlebar, fore-stock, front fork, front vehicle wheel, preceding slash, rear slash, whippletree, back vent, rear wheel and power drive system, institute State handlebar to be fixedly connected with front fork by the fore-stock, the front fork end is provided with the front vehicle wheel；The preceding slash One end is fixedly connected with sleeve, and the other end is fixedly connected with the whippletree, and the sleeve set prevents preceding branch on the fore-stock Frame slides axially along sleeve, and the fore-stock can rotate in sleeve；Connection bicycle seat in slash one end after described, separately One end is fixedly connected on the whippletree；Described whippletree one end is fixedly connected with the preceding slash, and the other end is to bicycle rear end Extension is fixedly connected with the back vent；Described back vent one end connects with the whippletree, and the other end is separated into forked, is fixedly connected with institute State rear wheel both sides；The power drive system include main lever, fixed plate, pedal, crank, flywheel, preceding fluted disc, rear tooth disk, Chain and the mechanism for reducing main lever amplitude of fluctuation, the main lever, fixed plate, pedal and the machine for reducing main lever amplitude of fluctuation Structure is respectively equipped with two groups, and is located at the both sides of bicycle respectively, and described main lever one end connects the pedal, the other end and described The mechanism for reducing main lever amplitude of fluctuation is connected by pitman shaft, and the main lever is fixed on described by the first lever fulcrum shaft In fixed plate, the main lever and first lever fulcrum shaft form laborsaving lever, the pedal attachment end of main lever to first Lever fulcrum shaft is lever moving arm, and main lever opposite side is lever resistance arm；The mechanism for reducing main lever amplitude of fluctuation For reducing the amplitude of fluctuation of main lever, and the power on the main lever resistance arm is passed on the crank and drives crank to turn Dynamic, the flywheel and preceding fluted disc are fixedly installed on the crank, and the pivot center and the crank of flywheel and preceding fluted disc Pivot center is overlapped, and the preceding fluted disc is connected with the rear tooth disk by chain, for the torque of preceding fluted disc to be transferred into rear tooth On disk, and then rear wheel is driven to rotate.

Further, it is described reduce main lever amplitude of fluctuation mechanism include the first lever, the second lever, the 3rd lever, 4th lever and the 5th lever, wherein first lever extends obliquely, one end is connected with the main lever by pitman shaft, The other end is connected with second lever by pitman shaft；Second lever is fixed on described solid by the second lever fulcrum shaft On fixed board, second lever one end and first lever form lever moving arm by connecting rod axis connection, the other end and described the Three levers form lever resistance arm by connecting rod axis connection；3rd lever extends obliquely, one end and second lever By connecting rod axis connection, the other end is connected on the 4th lever by pitman shaft；Described 4th lever one end passes through the 3rd Lever fulcrum shaft is fixedly connected in the fixed plate, and the other end passes through the 5th lever described in connecting rod axis connection；5th thick stick Bar one end is connected on the crank by the lever of connecting rod axis connection the 4th, the other end.

Further, the crank is provided with mobile jib, rotating shaft hack lever and power rail, and the mobile jib is located at the middle part of crank, main Bar both sides are equipped with flywheel and preceding fluted disc, and the power rail has two, respectively the eccentric position with the flywheel face, preceding fluted disc it is inclined Heart position is fixedly connected, and two power rails connect with the 5th lever positioned at bicycle both sides respectively, and the 5th lever can Being rotated around the power rail, the axis of described two power rails is located at the both sides of crank axis line, when riding, two power rails Corner phase differ 180 °, the rotating shaft hack lever has two, is respectively arranged on the both sides outermost of crank, the spindle housing bridge It is located on the fork branch of back fork of bicycle, and the axis of crank overlaps so that the crank being capable of the rotation of its axis.

Further, a length of 110~140cm of the main lever, a length of 15~25cm of the first lever, second thick stick A length of 20~the 30cm of bar, a length of 6~13cm of the 3rd lever, a length of 20~30cm of the 4th lever.

Further, the power arm lengths of the main lever：The ratio of resistance arm lengths is 12~15:1, second thick stick The power arm lengths of bar：The ratio of resistance arm lengths is 1~2:1, the power arm lengths of the 4th lever：Resistance arm lengths Ratio is 2.3~3.5:10.

Further, to reduce bicycle entire length, the outer rim of the rear wheel extends to the flywheel and preceding fluted disc Between gap.

Further, the diameter of the front vehicle wheel is less than the rear wheel, front vehicle wheel：The diameter ratio of rear wheel is：2:1 ~10:7.

Further, the main lever is curved relief portion, for avoiding main lever in swing process and the back vent phase Touch, and the height of pedal can be improved, avoid pedal and ground touching, the relief portion in ride from being located at main lever with after Close proximity is pitched, is U-shape structure, the recess of U-shape structure is down.

Further, article box is installed at the rear slash and whippletree, for store things；It is provided with the sleeve Bicycle basket.

Further, damping spring is installed, the seat is connected by expansion link with rear slash, described on the front fork Slash is hollow tube structure afterwards, and the expansion link can slide in rear slash, realizes the height regulation of the seat, described Slash is provided with fixing bolt afterwards, for fixing the expansion link.

As can be seen from the above technical solutions, the utility model has the advantages that：

1. the utility model drives bicycle to advance by lever drive, otherwise lever driven bicycle of the prior art The arm of force is inadequate, labor-saving effect unobvious, or driving treadle length, power arm is longer, laborsaving, but treadle amplitude of fluctuation is very big, Treadle end is easy to touch with ground.The utility model solves well by designing the mechanism for reducing main lever amplitude of fluctuation Above mentioned problem so that on the basis of bicycle keeps long power arm, avoid pedal and ground contact.

2. the utility model by designing the crank with flywheel, using the inertia and knockout press of flywheel, reaches further laborsaving Effect.Meanwhile the structure of crank is optimized, and solve and a treadle is often pedaled in existing design, the angle very little that flywheel turns over The problem of so that ride quite laborsaving, riding speed can reach per hour 30~40 kilometers and it is effortless, and climbing ride Also it is very light.

3. by largely attempting to test, in-house each thick stick of the utility model to the reduction main lever amplitude of fluctuation Bar size is studied, have found using effect it is optimal when each lever length value, optimize physical dimension.

4. the utility model structure design advantages of simple, compared to existing bicycle or electric car significant effect, no With charging, achievable long range is ridden, and saves energy environmental protection again.

Brief description of the drawings

It is required in being described below to embodiment in order to illustrate more clearly of the technical scheme of the utility model embodiment The accompanying drawing used is briefly described, it should be apparent that, drawings in the following description are only some implementations of the present utility model Example, for those of ordinary skill in the art, without having to pay creative labor, can also be according to these accompanying drawings Obtain other accompanying drawings.

Fig. 1 is structural representation of the present utility model；

Fig. 2 is the structural representation of crank described in the utility model.

Embodiment

Below in conjunction with the accompanying drawings, and in conjunction with the embodiments the utility model is described further.Retouched of the present utility model , it is necessary to explanation in stating, term " " center ", " longitudinal direction ", " transverse direction ", " on ", " under ", "front", "rear", "left", "right", " erect Directly ", the orientation of the instruction such as " level ", " top ", " bottom ", " inner side ", " outside " or position relationship are based on orientation shown in the drawings Or position relationship, only description the utility model and simplified description for convenience, rather than indicate or imply that signified device must have There is specific orientation, formed and operated with specific orientation, therefore it is not intended that to limitation of the present utility model.

As shown in figure 1, a kind of novel labour saving lever driven bicycle, including handlebar 1, fore-stock 2, front fork 34, front truck Wheel 3, preceding slash 4, rear slash 5, whippletree 6, back vent 7, rear wheel 11 and power drive system.Handlebar 1 is by fore-stock 2 with before Fork 34 is fixedly connected, and the end of front fork 34 is provided with front vehicle wheel 3.Preceding one end of slash 4 is fixedly connected with sleeve 35, the other end and whippletree 6 It is fixedly connected, sleeve 35 is sleeved on fore-stock 2, prevents the sliding axially along sleeve 35 of fore-stock 2.Fore-stock 2 can cover Rotated in cylinder 35.The one end of slash 5 connection bicycle seat 36, the other end are fixedly connected on whippletree 6 afterwards.The one end of whippletree 6 is with before Slash 4 is fixedly connected, and the other end extends to bicycle rear end to be fixedly connected with back vent 7.The one end of back vent 7 and whippletree 6 connect, another End is separated into forked, is fixedly connected with the both sides of rear wheel 11.The power drive system includes main lever 10, fixed plate 13, pedal 9th, crank, flywheel 12, preceding fluted disc 22, rear tooth disk 21, chain 20 and the mechanism for reducing main lever amplitude of fluctuation.Main lever 10, consolidate The mechanism of fixed board 13, pedal 9 and reduction main lever amplitude of fluctuation is respectively equipped with two groups, and is located at both sides (Fig. 1 of bicycle respectively In be difficult to check too much in order to avoid lines, only depict the structural representation of wherein side).The one end of main lever 10 connects pedal 9, the other end is connected with the mechanism of the reduction main lever amplitude of fluctuation by pitman shaft, and main lever 10 passes through the first balance pivot Axle 37 is fixed in fixed plate 13, and the lever fulcrum shaft 37 of main lever 10 and first forms laborsaving lever, and the pedal 9 of main lever 10 connects It is lever moving arm that end, which is connect, to the first lever fulcrum shaft 37, and the opposite side of main lever 10 is lever resistance arm.In addition, main lever 10 is curved There is relief portion 19, for avoiding main lever 10 from being collided in swing process with the back vent 7, and the height of pedal 9 can be improved, Pedal 9 and ground touching in ride are avoided, relief portion 19 is located at main lever 10 and the close proximity of back vent 7, is U-shaped knot Structure, the recess of U-shape structure is down.The mechanism for reducing main lever amplitude of fluctuation is used to reducing the amplitude of fluctuation of main lever, and by institute State the power on the resistance arm of main lever 10 and pass to drive crank rotation on crank.The mechanism for reducing main lever amplitude of fluctuation includes First lever 14, the second lever 15, the 3rd lever 16, the 4th lever 17 and the 5th lever 18.Wherein the first lever 14 is obliquely Extension, one end are connected with main lever 10 by pitman shaft, and the other end and the second lever 15 are connected by pitman shaft.Second lever 15 It is fixed on by the second lever fulcrum shaft 38 in fixed plate 13, the one end of the second lever 15 and the first lever 14 pass through connecting rod axis connection Form lever moving arm, the other end and the 3rd lever 16 and lever resistance arm is formed by connecting rod axis connection.3rd lever 16 is oblique Lower extension, one end and the second lever 15 are connected on the 4th lever 17 by connecting rod axis connection, the other end by pitman shaft.4th The one end of lever 17 is fixedly connected in fixed plate 13 by the 3rd lever fulcrum shaft 39, and the other end passes through the thick stick of connecting rod axis connection the 5th Bar 18.By the lever 17 of connecting rod axis connection the 4th, the other end is connected on the crank one end of 5th lever 18.As shown in Fig. 2 Crank is provided with mobile jib 28, rotating shaft hack lever 23 and power rail 27.Mobile jib 28 is located at the middle part of crank, and the both sides of mobile jib 28 are equipped with flywheel 12 With preceding fluted disc 22, the power rail 27 has two, respectively the eccentric position of the eccentric position with the face of flywheel 12, preceding fluted disc 22 It is fixedly connected, two power rails 27 connect with the 5th lever 18 positioned at bicycle both sides respectively, and the 5th lever 18 can surround Power rail 27 rotates, and the axis of two power rails 27 is located at the both sides of crank axis line.When riding, the corner of two power rails 27 Phase differs 180 °, and rotating shaft hack lever 23 has two, is respectively arranged on the both sides outermost of crank, and rotating shaft hack lever 23 is erected at bicycle On the fork branch of back vent 7, and the axis of crank overlaps so that crank being capable of the rotation of its axis.Flywheel 12 and preceding fluted disc 22 are solid Surely it is arranged on crank, and the pivot center of the pivot center and crank of flywheel 12 and preceding fluted disc 22 overlaps, preceding fluted disc 22 is with after Fluted disc 21 is connected by chain 20, for the torque of preceding fluted disc 22 to be transferred into rear tooth disk 21, and then drives 11 turns of rear wheel It is dynamic.

Optimize the size of each main lever in the mechanism of the reduction main lever amplitude of fluctuation so that when user's right crus of diaphragm collapses When lower pedal is to extreme lower position, the power rail on the right side of crank also reaches extreme lower position, and the power rail on the left of crank rises to highest Position, and then the pedal on the left of bicycle reaches extreme higher position.Correspondingly, when user the pedal in left side stepped on it is minimum During position, the pedal on right side, which is stepped on, returns to highest position, completes a circulation.To realize this effect, size design is as follows：It is main 10 a length of 123cm of lever, 14 a length of 20cm of the first lever, 15 a length of 26cm of the second lever, the 3rd lever 16 a length of 10cm, the 4th 17 a length of 26cm of lever；The power arm lengths of main lever 10：The ratio of resistance arm lengths is 115cm:8cm, the second lever 15 The length of power arm：The ratio of resistance arm lengths is 15cm:11cm, the length of the power arm of the 4th lever 17：Resistance arm lengths Ratio be 7cm:26cm.

To reduce the overall size of bicycle, the detailed structure of bicycle is optimized, the outer rim of rear wheel extends to flywheel In space between 12 and preceding fluted disc (22).The diameter of front vehicle wheel 3 is less than rear wheel 11, front vehicle wheel (3)：Rear wheel (11) it is straight The ratio between footpath is：58cm：36cm.

In addition, for the ease of using so that the usability and level of comfort of bicycle are more preferable.At rear slash 5 and whippletree 6 Article box 30 is installed, for store things；Bicycle basket 33 is installed on sleeve 35；Damping spring is installed on front fork 34 32, seat 36 is connected by expansion link and rear slash 5, and rear slash 5 is hollow tube structure, and expansion link can be in rear slash 5 Slide, realize the height regulation of the seat 36, rear slash 5 is provided with fixing bolt 8, for fixing the expansion link.It is preceding oblique Thick stick 4 is provided with deep bead 31, and bicycle is additionally provided with back seat 25, as shown in Figure 1.

In use, bicyclist steps on right pedal, main lever is swung, and due to leverage, drives the first lever to move upwards. Power on main lever resistance arm is sent to the kinetic moment that the second lever is formed on the second lever by the first lever, then passes through the second thick stick The leverage of bar transmits the force to the 3rd lever, and then the 3rd lever transmits the force to the 4th lever, forms the 4th lever Kinetic moment.Torque is sent on the 5th lever by the 4th lever by leverage, and then drives crank rotation, realizes trailing wheel Rotate, promote bicycle to advance.

Technical scheme provided by the utility model is described in detail above, for the general technology people of this area Member, according to the thought of the utility model embodiment, there will be changes in specific embodiments and applications, to sum up institute State, this specification content should not be construed as to limitation of the present utility model.

Claims (10)

1. a kind of novel labour saving lever driven bicycle, including handlebar (1), fore-stock (2), front fork (34), front vehicle wheel (3), Preceding slash (4), rear slash (5), whippletree (6), back vent (7), rear wheel (11) and power drive system, the handlebar (1) are logical Cross the fore-stock (2) to be fixedly connected with front fork (34), front fork (34) end is provided with the front vehicle wheel (3)；Before described Slash (4) one end is fixedly connected with sleeve (35), and the other end is fixedly connected with the whippletree (6), and the sleeve (35) is sleeved on institute State on fore-stock (2), prevent fore-stock (2) sliding axially along sleeve (35), the fore-stock (2) can be in sleeve (35) Rotate；Slash (5) one end connection bicycle seat (36), the other end are fixedly connected on the whippletree (6) after described；The horizontal stroke Thick stick (6) one end is fixedly connected with the preceding slash (4), and the other end extends to bicycle rear end to be fixedly connected with the back vent (7)； Described back vent (7) one end and the whippletree (6) connection, the other end is separated into forked, is fixedly connected with the rear wheel (11) both sides； Characterized in that, the power drive system includes main lever (10), fixed plate (13), pedal (9), crank, flywheel (12), preceding Fluted disc (22), rear tooth disk (21), chain (20) and the mechanism for reducing main lever amplitude of fluctuation, the main lever (10), fixed plate (13), the mechanism of pedal (9) and reduction main lever amplitude of fluctuation is respectively equipped with two groups, and is located at the both sides of bicycle, institute respectively State main lever (10) one end and connect the pedal (9), the other end and the mechanism for reducing main lever amplitude of fluctuation pass through connecting rod Axle is connected, and the main lever (10) is fixed in the fixed plate (13) by the first lever fulcrum shaft (37), the main lever (10) and first lever fulcrum shaft (37) forms laborsaving lever, pedal (9) connection end of main lever (10) to the first lever Fulcrum shaft (37) is lever moving arm, and main lever (10) opposite side is lever resistance arm；The reduction main lever amplitude of fluctuation Mechanism is used for the amplitude of fluctuation for reducing main lever, and the power on the main lever (10) resistance arm is passed on the crank and driven Crank is rotated, and the flywheel (12) and preceding fluted disc (22) are fixedly installed on the crank, and flywheel (12) and preceding fluted disc (22) Pivot center and the crank pivot center overlap, the preceding fluted disc (22) and the rear tooth disk (21) pass through chain (20) Connection, for the torque of preceding fluted disc (22) to be transferred into rear tooth disk (21), and then rear wheel (11) is driven to rotate.

A kind of 2. novel labour saving lever driven bicycle according to claim 1, it is characterised in that the reduction main lever The mechanism of amplitude of fluctuation includes the first lever (14), the second lever (15), the 3rd lever (16), the 4th lever (17) and the 5th thick stick Bar (18), wherein first lever (14) extends obliquely, one end is connected with the main lever (10) by pitman shaft, another End is connected with second lever (15) by pitman shaft；Second lever (15) is fixed by the second lever fulcrum shaft (38) In the fixed plate (13), the second lever (15) one end and first lever (14) form lever by connecting rod axis connection and moved The arm of force, the other end and the 3rd lever (16) form lever resistance arm by connecting rod axis connection；3rd lever (16) is oblique Extend downwardly, one end and second lever (15) are connected to the described 4th by connecting rod axis connection, the other end by pitman shaft On lever (17)；Described 4th lever (17) one end is fixedly connected on the fixed plate (13) by the 3rd lever fulcrum shaft (39) On, the other end passes through the 5th lever (18) described in connecting rod axis connection；Described 5th lever (18) one end passes through connecting rod axis connection Four levers (17), the other end are connected on the crank.

3. a kind of novel labour saving lever driven bicycle according to claim 2, it is characterised in that the crank is provided with master Bar (28), rotating shaft hack lever (23) and power rail (27), the mobile jib (28) are located at the middle part of crank, and mobile jib (28) both sides are equipped with winged Wheel (12) and preceding fluted disc (22), the power rail (27) have two, respectively with eccentric position, the preceding fluted disc in the flywheel (12) face (22) eccentric position is fixedly connected, and two power rails (27) connect with the 5th lever (18) positioned at bicycle both sides respectively, 5th lever (18) can surround the power rail (27) and rotate, and the axis of described two power rails (27) is located in crank The both sides of axis, when riding, the corner phase of two power rails (27) differs 180 °, and the rotating shaft hack lever (23) has two, point Not She Yu crank both sides outermost, the rotating shaft hack lever (23) is erected on the fork branch of back fork of bicycle (7), and in crank Axis overlaps so that the crank being capable of the rotation of its axis.

A kind of 4. novel labour saving lever driven bicycle according to claim 2, it is characterised in that the main lever (10) A length of 110~140cm, a length of 15~25cm of first lever (14), second lever (15) a length of 20~30cm are described 3rd lever (16) a length of 6~13cm, a length of 20~30cm of the 4th lever (17).

5. a kind of novel labour saving lever driven bicycle according to any one of claim 2~4, it is characterised in that described The power arm lengths of main lever (10)：The ratio of resistance arm lengths is 12~15:1, the power brachium of second lever (15) Degree：The ratio of resistance arm lengths is 1~2:1, the power arm lengths of the 4th lever (17)：The ratio of resistance arm lengths is 2.3~3.5:10.

6. a kind of novel labour saving lever driven bicycle according to claim 5, it is characterised in that whole to reduce bicycle Body length, the gap that the outer rim of the rear wheel is extended between the flywheel (12) and preceding fluted disc (22).

A kind of 7. novel labour saving lever driven bicycle according to claim 5, it is characterised in that the front vehicle wheel (3) Diameter be less than the rear wheel (11), front vehicle wheel (3)：The diameter ratio of rear wheel (11) is：2:1~10:7.

A kind of 8. novel labour saving lever driven bicycle according to claim 5, it is characterised in that the main lever (10) It is curved to have relief portion (19), for avoiding main lever (10) from being collided in swing process with the back vent (7), and pedal can be improved (9) height, pedal in ride (9) and ground is avoided to touch, the relief portion (19) is located at main lever (10) and back vent (7) close proximity, it is U-shape structure, the recess of U-shape structure is down.

A kind of 9. novel labour saving lever driven bicycle according to claim 5, it is characterised in that slash (5) after described Article box (30) is installed with whippletree (6) place, for store things；Bicycle basket (33) is installed on the sleeve (35).

A kind of 10. novel labour saving lever driven bicycle according to claim 5, it is characterised in that the front fork (34) On damping spring (32) is installed, the seat (36) is connected by expansion link and rear slash (5), it is described after during slash (5) is Blank pipe body structure, the expansion link can slide in rear slash (5), the height regulation of the seat (36) be realized, after described Slash (5) is provided with fixing bolt (8), for fixing the expansion link.