CN85105841A

CN85105841A - Bicycle speed-varying unit

Info

Publication number: CN85105841A
Application number: CN 85105841
Authority: CN
Inventors: 沈一鹏
Original assignee: JOINT INDUSTRY-TRADE CHANGZHOU BICYCLE GENERAL FACTORY
Current assignee: JOINT INDUSTRY-TRADE CHANGZHOU BICYCLE GENERAL FACTORY
Priority date: 1985-07-31
Filing date: 1985-07-31
Publication date: 1986-07-16
Also published as: CN85105841B

Abstract

The invention relates to change-speed box, particularly the invention of bicycle sprocket variable transmission.This change-speed box is that a free-wheel clutch that is contained in the right bottom bracket cup projecting end of bicycle is arranged, on the outer cylinder surface of power-transfer clutch, connect a face cam, pair of sprocket slide block and a pair of idler roller block one end have short cylindrical pin and two cyclic curve groove engagements of face cam end face of stretching out, the other end has and extends key and engage with corresponding radially guide groove on the crank drive disc that is connected in the axis right-hand member, and the angle of lead at crank center sprocket slider long diameter channel center (α) is 20～60 to spend.The bicyclist carries out the conversion of transmission speed by back-pedalling, is just pedaling then by the speed change ellipse of selected corresponding effective diameter (or circle) shape chain wheel drive bicycle running.

Description

Bicycle speed-varying unit

The invention relates to change-speed box, particularly the invention of bicycle sprocket variable transmission.

Using bicycle speed-varying unit is according to the change as the human body muscular strength characteristic of power driven bicycle and the condition of riding at that time (speed, the gradient, condition of road surface, wind direction etc.), the perhaps requirement of riding that foundation is different (speed match, increase body burden-health care exercise etc.) is converted to the optimum condition of situation at that time that adapts to the characteristic of bicycle, reaches the good purpose of the usefulness of riding.

A kind of known automated variable sprocket transmission is arranged.This change-speed box can be according to bicyclist's the automatic conversion transmission speed ratio of the power of pedaling size, but this change-speed box is difficult to the requirement of riding of the bicyclist of the different physical quality of simultaneous adaptation or the same bicyclist difference under not congeniality, muscle power, competitive state, perhaps complex structure, weight increase, adjust difficulty, are not easy to Quantity production and use.Other has the change-speed box of American Roy Si (RoyceH) invention of announcing a kind of April 28 nineteen eighty-three in world patent W083/01424.This change-speed box is by a drive plate, one with a pair of fan-shaped sprocket slide block, a pair of gear on stud slide block and a variable chains wheel speed of forming with the coaxial relatively turnable face cam that has at least 4 helix wave grooves of drive plate, the bicyclist can be by the positive and negative speed change of pedaling of pedal, and is simple and reliable for structure.But this change-speed box bicyclist when speed change must be arranged on auxiliary handle on the handlebar with hand operation, through steel cable grip is passed to brake system and pins face cam, and both feet cooperate and just pedal (raising speed) back-pedalling (reduction of speed) and select transmission speed ratio simultaneously; In addition, during this known transmission speed change, each quadrant block is generally only made the effective diameter of the equal radial expansion conversion driving chain wheel of ratio.This is because each group location concave edge of several helix wave grooves of control quadrant block effective diameter position, be difficult to guarantee both to have met simultaneously the snail function, meet elliptic function again, and the pitch circumference that makes effective ellipse wheel of setting satisfies and the ratio of its ingear driving chain pitch is that conditions such as overlapping phenomenon all must not appear interfering mutually in the adjacent positioned concave edge (comprising between same plug helix or adjacent plug helix) of several helix wave grooves on natural number and the face cam, and in fact this known transmission will realize when carrying out speed change that the ellipse wheel transmission is to be subjected to the restriction of above-mentioned each side and to be difficult to realize satisfactory results.Also have the invention about bicycle chainwheel of announcing in French Patent (FRP) 2501146 a kind of September 10 nineteen eighty-two, this invention has proposed a kind of ellipse wheel that can alleviate bicyclist's fatigue, promote the bicycle output performance.This ellipse wheel can require to form the multi-disc chain wheel set that is applicable to bicycle external gear-shaft according to the different numbers of teeth, group chain device by outer change-speed box, with this multi-disc chain wheel set ingear driving chain, transform to another ellipse wheel sheet from an ellipse wheel sheet, finish the function of transmission rate variation, but the number of teeth of this ellipse wheel itself can not change.So this ellipse wheel can not self be finished the conversion of transmission speed ratio, also just can not eliminate the complex structure of the outer change-speed box of above-mentioned structure, be difficult to make with transmission middle sprocket and chain can not be all the time all in same plane engaged transmission and the noise that causes, be easy to weak points such as wearing and tearing, driving efficiency reduction.

Task of the present invention is that a kind of variable chains wheel speed that is specially adapted to bicycle is provided.This change-speed box only needs the bicyclist to reverse by pedal, conversion transmission speed ratio successively just, and can form ellipse (or circle) the shape chain sprocket drive of corresponding effective diameter (number of teeth) simultaneously by selected transform.

Its solution is: change-speed box of the present invention adopts the right bottom bracket cup projecting end cover at bicycle to load onto a free-wheel clutch, connecting one coaxially with axis on the outer cylinder surface of this power-transfer clutch both can rotate with the axis synchronous forward, can be locked in again on the right bottom bracket cup the static relatively face cam of cycle frame during the axis counter-rotating, on the right side of this face cam, according to the requirement that to satisfy its effective joint garden girth be driving chain pitch natural multiple of oval (or circle) shape driving chain wheel (as for the shape of these " ellipses " or " circle " as why not being topmost), leave two osed top band radial symmetry distributions that join end to end separately and determine the inside and outside cyclic curve groove of the positioning round orifice of driving chain wheel diameter (number of teeth) parameter, pair of sprocket slide block and another are to the mutual vertical distribution of idler roller block, have on the slide block short cylindrical pin that stretches out respectively with outcurve wire casing and introversion wire casing bearing fit, the other end of sprocket slider and idler roller block has the key of extension, engages with "+" font driver slot on the crank drive disc that is connected in the axis right-hand member respectively.

Like this, when the bicyclist was just being pedaled crank pedal, face cam just can be rotated in the forward around axis synchronously with right bottom bracket cup disengagement and with crank drive disc, sprocket slider, drives bicycle rear and travels by usual chain, flywheel.Bicyclist's back-pedalling crank pedal, face cam is locked on the right bottom bracket cup immediately, driving disk drove and dialled sprocket slider to right with idler roller block this moment, make radial expansion respectively by two curved grooves and the corresponding knock hole set on the face cam, ellipse (or circle) the shape sprocket wheel in various long and short footpaths is formed in conversion successively.The change of driving chain wheel girth is by expansion tightening wheel compensation commonly used during speed change.

As mentioned above, variable chains wheel speed of the present invention is when finishing the transmission speed ratio conversion, also realized oval (or circle) shape chain sprocket drive, the natural characteristic that alternately scrunches this " biological engine " with human body is complementary, and makes the utilization of bicyclist's muscular strength energy can obtain the actv. enhancement.Another advantage of the present invention is: this change-speed box is when carrying out speed change, no longer need to be provided with manually control coupling mechanism such as handle, steel cable, drg, also no longer needed trick while united control, make speed changer structure of the present invention simplify greatly, be suitable for large-scale industrial production, manipulate also convenient, the bicyclist at any time all can energy concentrated area both hands holds safety is ridden, and can be under the parking quiescence speed change, thereby can avoid when stopping, often causing because of maloperation general outside the structural damage that runs into usually of change-speed box.

An improvement related to the present invention is, because this change-speed box does not have derailleur or other hand shift actuation mechanism etc. to be associated with driving chain wheel, so purpose made whole chain cover of affix at an easy rate, the bicycle transmission gear shift system that comprises variable chains wheel speed, driving chain, expansion tightening wheel, flywheel is enclosed in the whole chain cover book shell chamber, realize the enclosed transmission, this transmission gear shift system can be reduced wear, improve reliability, be more suitable for all-weather service.

Accompanying drawing has been described one embodiment of the present of invention.

Fig. 1: bicycle transmission gear shift station diagram.

Fig. 2,3: the parameter legend of ordinary bicycle, sports bicycle angle of lead (α).

Fig. 4: change-speed box front elevation.

Fig. 5: along the cutaway view of the long and short footpath A-A of the variable sprocket wheel of change-speed box.

Fig. 6: forward and partial view that face cam, free-wheel clutch connect with right bottom bracket cup.

Fig. 1 has described the transmission connection and the interrelation of bicycle speed-varying unit.Change-speed box (1) is installed on the axis (2), the bicyclist is by just pedaling pedal (9), with legpower by crank (10) drive torque around axis (2) rotation, major diameter (8) minor axis (7) (when major diameter (8) and minor axis (7) are circular chain-wheel when equating) of the effective drive diameter by the selected ellipse of change-speed box (1) conversion (or circle) shape sprocket wheel, drive bicycle rear (6) rotation for flywheel (5) transmission of power by usual driving chain (3), promote bicycle running.For the muscular strength that makes the bicyclist is rationally utilized, crank (10) center is 20～60 ° to the angle of lead (α) of ellipse wheel major diameter (8).

The concrete of angle of lead (α) selected, should be according to scrunching the best output state of having an effect of attitude decision by the bicyclist shown in Fig. 2,3: crank (10) be crossed after top dead center, when bicyclist's forefoot was crossed the power of pedaling that the widely different commentaries on classics of pedal (9) center applies approximately perpendicular to crank (10), the major diameter of ellipse wheel (8) should be in the position of general tangential with driving chain (3).This and bicyclist's stature selects for use the adjustment etc. of pattern, specification, saddle and handlebar height and position of bicycle closely related; Except can answer the bicyclist require special customized, can determine that usually Fig. 2, Fig. 3 show the parameter that ordinary bicycle and sports bicycle suit with the corresponding change angle of lead (α) of bicyclist's attitude respectively by the type of bicycle substantially.

Fig. 4,5,6 have described variable chains wheel speed (1), be to be bearing among right bottom bracket cup of ball (28) (27) and the figure on the unillustrated left bottom bracket cup by an axis (2), right bottom bracket cup (27) is captiveed joint with vehicle frame (29), a free-wheel clutch (32) is bound up between right bottom bracket cup (27) and the face cam (11) coaxial with axis (2), crank (10) driving disk (25) is connected in axis (2) right-hand member by pin (26), the idler roller block (20) of pair of sprocket slide block (12) and a pair of distribution that is perpendicular to one another is by the short cylindrical pin (14 that stretches out separately, 22) respectively with face cam (11) on outcurve wire casing (16) and introversion wire casing (18) is sliding joins, the other end of sprocket slider (12) and idler roller block (20) has extension key (13,21) engage with major diameter driver slot (15) minor axis driver slot (23) on the driving disk (25) respectively, for making inside and outside curved groove (18,16) do not interfere with each other, short cylindrical pin (22) on short cylindrical pin (14) on the sprocket slider (12) and the idler roller block (20) is unequal apart from the distance of variable sprocket wheel (24) pitch circle, short cylindrical pin (14) from nearer, short cylindrical pin (22) is from must be far away.

When the bicyclist is just being pedaled, by the length on crank (10) driving disk (25), minor axis driver slot (15,23) driving variable ellipse (or circle) the shape sprocket wheel (24) of dialling sprocket slider (12) idler roller block (20) and forming rotates around axis (3), power is passed to flywheel (5) through driving chain (3), and under the tension force effect of chain (3) its radial component with idler roller block (20) sprocket slider (12) through short cylindrical pin (22,14) be locked in the inside and outside curved groove (18 of face cam (11) respectively, the circular knock hole (19 of corresponding radial symmetry 16), 17) go up on the nock limit at axis (2) center, drive face cam (11) thus and throw off that usual used the sort of ratchet (30) ratchet (31) type free-wheel clutch (32) rotates synchronously with axis (2) in the bicycle freewheel (5).

During speed change, the bicyclist only needs back-pedalling crank (10), length on the driving disk (25), minor axis driver slot (15,23) drive group sprocket slider immediately, idler roller block (12,20) together around axis (2) contrarotation, and sprocket slider, idler roller block (12,20) hold the short garden pin (14 that stretches out, 22) drive group face cam (11) counter-rotating respectively simultaneously, ratchet (31) in this moment free-wheel clutch (32) pulls ratchet (30) and forces face cam (11) to be locked in right bottom bracket cup (27) to go up relative static with cycle frame (29) maintenance, along with the bicyclist continues back-pedalling, sprocket slider, idler roller block (12,20) begin to skid off original knock hole nock limit, and press face cam (11) and go up inside and outside curved groove (18,16) and the knock hole (19 of radial symmetry, 17) ellipse (or circle) the shape sprocket wheel (24) of required effective drive diameter is selected and obtained to correspondence position, and under the tension force effect of driving chain (3), its radial component forces sprocket slider, the ellipse slide block (12 of taking turns, 20) the short cylindrical pin (14 that stretches out on, 22) be locked in corresponding knock hole (17 selected again on the face cam (11) respectively, 19) on nock limit, axis (2) center, till next speed change begins.

It should be noted that speed change should be that one of sprocket slider (12) center of symmetry is under the non-engagement state with driving chain (3) and carries out (promptly having only a sprocket slider (12) and driving chain (3) ingear interval to carry out) making the major diameter of ellipse wheel (8).Because the position, angle between crank (10) and sprocket slider (12) has just no longer changed once determining, thus the bicyclist once examination ride just can grasp speed change habitually very soon the time double-legged should locate scrunch bearing range.

Fig. 4,5,6 provides the enforcement case of speed grade 12 grades of uniform variable chains wheel speeds, and 11 grades of wherein bigger variable sprocket wheels constitute ellipse wheels, and the corresponding virtual number of teeth of its maximum major diameter is 54 teeth; Minimum one-level constitutes circular chain-wheel, and the number of teeth is 32 teeth.The designer can choose number of steps of speeds as required, determine speed range by maximum sprocket wheel effective diameter and the decision of minimum sprocket wheel effective diameter, branches such as employing speed shelves or non-five equilibrium speed shelves and ellipse or circular variable sprocket form etc., designing the similar therewith variable chains wheel speed of different parameters, all is conspicuous.

Claims

1, change-speed box, bicycle sprocket variable transmission particularly, an axis that is bearing on the left and right bottom bracket cup is arranged, a crank drive disc is being connected in the axis termination, facing to driving disk a face cam in parallel and coaxial mounted is arranged, pair of sprocket slide block and another are clipped between driving disk and the face cam the idler roller block that distributes that is perpendicular to one another, sprocket slider to idler roller block to moving radially its radial location of conversion along axis respectively, rotate with driving disk, axis simultaneously.It is characterized in that: have a free-wheel clutch (32) to connect between face cam (11) and the right bottom bracket cup (27), face cam (11) can be rotated in the forward with axis (2), and face cam (11) is locked on the right bottom bracket cup (27) during axis (2) counter-rotating.

2, according to the change-speed box of claim 1, it is characterized in that: on face cam (11), have two inside and outside cyclic curve grooves of the osed top that joins end to end separately (18,16).

3, according to the change-speed box of claim 1 or 2, it is characterized in that: last two the cyclic curve grooves of face cam (11) (18,16) are radial symmetry.

4, according to the change-speed box of claim 1 or 2, it is characterized in that: have positioning round orifice (19,17) in last two the cyclic curve grooves of face cam (11) (18,16).

5, according to the change-speed box of claim 1 or 2, it is characterized in that: the positioning round orifice (19,17) that has in last two the cyclic curve grooves of face cam (11) (18,16) is that radial symmetry distributes.

6, according to the change-speed box of claim 1 or 2, it is characterized in that: determine that by respectively organizing positioning round orifice (19,17) on the face cam (11) sprocket slider (12) idler roller block (20) of effective radial location can form the transmission ellipse in each corresponding long and short footpath (or circle) shape sprocket wheel (24), and the ratio of its pitch circumference and driving chain (3) pitch is natural number.

7, according to the change-speed box of claim 1 or 2, it is characterized in that: have orthogonal major diameter driver slot (15) and minor axis driver slot (23) on the driving disk (25), crank (10) line of centers is 20～60 degree to the angle of lead (α) of major diameter driver slot (15) line of centers on the driving disk (25).

8, according to the change-speed box of claim 1 or 2, it is characterized in that: the short cylindrical pin (22) on short cylindrical pin (14) on the sprocket slider (12) and the idler roller block (20) is unequal apart from variable sprocket wheel (24) pitch circle.

9, according to the change-speed box of claim 1 or 2, it is characterized in that: the short cylindrical pin (14) on the sprocket slider (12) is nearer from variable sprocket wheel (24) pitch circle, and the short cylindrical pin (22) on the idler roller block (20) is far away from variable sprocket wheel (24) pitch circle.