CN85107819A - Centrifugal clutch - Google Patents

Abstract

The centrifugal clutch that can avoid between internal gear and clutch hub, producing the vibration sound.The shock absorber of manufacturing with elastic material is equipped with on internal gear or the clutch hub.With before corresponding eccentric otch sidewall on the internal gear contacts, shock absorber is in a circumferential direction earlier with on wheel hub or internal gear contact at the cam on the clutch hub.

Description

Centrifugal clutch

The invention relates to a kind of centrifugal clutch.It transmits power between friction plate and the power output shaft by a device that friction plate is housed, this device is made up of two-part, these two-part be with the internal gear of power output gear engagement and with the wheel hub that internal gear fits loosely in, adopt this device exactly will be when piloting engine friction plate to be shifted onto on the position that clutch closes.

Smaller two-wheel vehicle or tricycle always all are in the end of engine crankshaft a centrifugal clutch to be installed, and this crankshaft is as input shaft.

An exemplary of this centrifugal clutch can not authorized among the bulletin NO.75331/1981 in Japanese Utility Model and seen.There is a clutch casing to be installed on the cylindrical of input shaft at the centrifugal clutch shown in this model utility bulletin, can turn round with input shaft, also have a power output gear to fit loosely in the other part cylindrical of input shaft, in addition, on the clutch casing inner circumferential surface, also has axially movable clutch-plate.The internal gear that is meshed with power output gear is installed on the external peripheral surface of clutch casing.The clutch hub that supports friction plate is installed on the cylindrical of internal gear.

Like this, two component configuration are arranged between friction plate and power output gear on this centrifugal clutch that everybody has the knack of, Here it is: internal gear and clutch hub.Adopting this collocation method is in order friction plate and clutch-plate to be abutted against together mutually, thereby makes engine start.More definite ground say, as shown in Figure 5, make the cam 36(on internal gear 14 external peripheral surfaces outstanding from the internal gear exactly) be close to mutually with eccentric otch 35 on clutch hub 13 inner circumferential surfaces.Eccentric otch has two relative sidewall 35a, 35b, and the cam 36 that matches between them can along the circumferential direction move, and in addition, has the gauge finder face 35C of a band gradient to tilt at axial direction, will be close to mutually with cam 36.The work of this device is such, when operation according to the Kick-start device, drive internal gear 14 when direction shown in the arrow X is turned round by power output gear, cam 36 just slides on the gauge finder face 35C of band gradient, move vertically thereby promote clutch casing 13, clutch is closed.Meanwhile, cam 36 also is pressed on the gauge finder face 35C at circumferencial direction, pilots engine thereby transmit a moment.

Motor is in case by after the starting of Kick-start device, the moment of motor is just transmitted with opposite order, thereby clutch hub 13 turns round towards direction shown in the arrow Y, cam 36 is slided along the gauge finder face 35C of band gradient, be close to mutually with the sidewall 35a of eccentric otch 35, so just set up normal power delivery status, promptly the power of motor is passed to output shaft by internal gear 14.

Like this, on this device that everybody has the knack of, it only is by being close between cam 36 and the eccentric otch 35 that the power between internal gear 14 and the clutch hub 13 transmits.But, regrettably this device has some following shortcomings.

Its shortcoming just is to be in neutral position so that when making the race of engine when power transfer device, and clutch can be automatically separately, because rotating speed is low, centrifugal force is too little.However, clutch hub 13 also can have rotating trend because of friction, this is pass to friction plate owing to existing oil in the clutch can allow little power from clutch-plate on the one hand, also be because friction plate tends to contact with clutch-plate is local slightly on the other hand, this is because of having certain little gap between the wheel hub 13 that is contained at internal gear 14 and loose ground on the internal gear.

Because internal gear 14 is not load-carrying in this case, be freely, so internal gear 14 also can be with and turn round by the friction of clutch hub 13, go out the same state that phenomenon the sort of normal output shown in Figure 6 transmits.

So, because the friction of unloaded internal gear 14,, between the sidewall 35a of eccentric otch 35 and cam 36, will often cause to contact or collide also because the fluctuation of crankshaft rotating speed, thus vibrative noise.

Therefore, one object of the present invention is exactly the centrifugal clutch that a kind of above-mentioned pattern will be provided, thereby it will improve the sound that can avoid producing the sort of vibration.

For this purpose, to provide a kind of centrifugal clutch according to the present invention with shock absorber, sort buffer spare system is manufactured by elastic material, can be contained on the internal gear, also can install on the clutch hub, adopting more such shock absorbers is exactly before will bumping in the respective side walls of cam on the internal gear and eccentric otch, and shock absorber contacts with wheel hub or these parts of internal gear earlier.

Shown in Figure 1 is the sectional view of the system of power transmission of small-sized two-wheel car when using clutch in the embodiment of the invention;

The sectional drawing that is Fig. 1 along II-II shown in Figure 2, this is the state that pedal is fired an engine;

The sectional drawing that is Fig. 1 along II-II shown in Figure 3, this is to be under the state of buffering or normal transmission of torque;

The sectional drawing that is Fig. 1 along II-II shown in Figure 4, this is the state before buffering;

Shown in Figure 5 be a general clutch under the Kick-start state,

Shown in Figure 6 is that general clutch is under normal moment transmit mode.

With reference to Fig. 1, show a limit portion of the crankcase 1 of motor E on the figure.Crankcase 1 is supporting a crankshaft 2, and crankshaft can rotate and as the input shaft of clutch.A jack shaft 3 and a power output shaft 4 also are housed on crankcase 1, and they all parallel with crankshaft 2.

Under situation represented on the figure, first to the 3rd speed changing transmission gear 5A, 5B and 5C are installed on jack shaft 3.Second power output gear 7 of band damping spring 6 is installed in jack shaft 3 and stretches out crankcase 1 end in addition.

On the other hand, with corresponding speed changing transmission gear 5A, the speed change driven gear 8A that 5B and 5C are meshed, 8B and 8C are installed on the power output shaft 4.The gear that speed changing transmission gear 5A-5C, speed change driven gear 8A-8C do not show on other figure has constituted a transmission device that can change speed.

A backflushing type starting arrangement (not showing on the figure) is connected on first speed changing transmission gear 8A, and this gear is installed in the right-hand member of power output shaft 4, as shown in Figure 1.

On the other hand, in a limit portion of crankcase 1 clutch housing 9 is housed.This outer cover 9 adapts to centrifugal clutch C, and this is illustrated below.

Centrifugal clutch C is installed in an end of bent axle 2, mainly is made up of clutch casing 10, clutch-plate 11, friction plate 12, clutch hub 13, internal gear 14 and garter spring 15.

In above-mentioned these critical pieces, clutch casing 10 is to manufacture with the aluminum or aluminum alloy of die casting, and heart tapping has keyway therein, is contained in the end of crankshaft 2, and end of crank screw on a nut 16 in case on-slip go out.

Center hub 17 is housed, sidewall and outside circumference housing 19 around the wheel hub 17 on the clutch casing 10.The groove 20 of a support spring that forms on sidewall 18 internal surfaces is used for placing that garter spring 15.The radial outer wall of the groove of this support spring has a tapering towards clutch-plate 11, thereby has formed a gauge finder face 21, and it is generally tapered.

On the other hand, have a series of boss 22 to be used for inserting clutch-plate on the internal circular surfaces of clutch casing outside circumference housing 19, at intervals, these boss are stretched in radial direction inwards from circumference housing 19 on circumference, and this sees the most clearly in Fig. 2.As shown in Figure 1, insert first end clutch-plate 23 of close garter spring 15 in each boss 22 there, apart from garter spring 15 farthest first end clutch-plate 25 and the clutch-plate 11 of two centres, clutch-plate 11 is between the centre of end clutch- plate 23 and 25 in the middle of these two.These clutch- plates 23,11,11 and 25 can only slide in radial direction.Baffle ring of fixing by boss 22 of on the figure 26 expression.Between this baffle ring 26 and second end clutch-plate 25, a disc spring 27 is housed, makes clutch-plate be in the position of " clutch closes ", just can the position of carry-over moment on.Have on the inner circumferential surface of circumference housing 19 outside some the guiding wheel hubs 28, between adjacent lands 22 at intervals.In these guiding wheel hubs pin rod 29 is housed and is used for making clutch-plate 11 and friction plate 12 to be separated from each other, these pin rods are handled by a clutch operation 30, and this mechanism moves at both direction by a foot treadle.This structure is design like this, and when pedal stepped down, clutch separated pin rod and just moves, and the elastic force that makes second end clutch-plate 25 overcome disc spring 27 moves on on the position of " clutch separately ".

Some grip slippers 31 are arranged on the circumferential surface of the outside of clutch hub 13.These grip slippers are used for fixing friction plate 12 and it can axially be free to slide.The core of friction plate 12 is to manufacture with general purpose cold rolled sheet, and bag is with cork type high-abrasive material 32 on the both sides of steel plate and outer surface.

On clutch hub 13 outside circumferential surfaces a press flange 33 is arranged, this flange is positioned at an axial end of wheel hub, faces friction plate 12.As can see from Figure 2, three eccentric otch 35 are arranged on the inner circumferential surface of clutch hub 13, these otch are equidistant on circumference.

These eccentric otch 35 be used for internal gear 14 outside circumferential surfaces on corresponding cam 36 be close to mutually.Each eccentric otch 35 all has two relative sidewall 35a and 35b, and the corresponding cam 36 of making separated by a distance therebetween moves at circumferencial direction, in addition, also has the gauge finder face 35C in the axial zone gradient.

When the backflushing type starting arrangement of saying with the front time with engine start, starting power is by first speed change driven gear 8A, first speed changing transmission gear 5A and second power output gear 7 are sent on first power output gear 37, this gear is contained on the cylindrical of crankshaft 2, so just a moment is delivered on the internal gear 14 from first power output gear 37, thereby the cam 36 on the internal gear 14 is slided on the gauge finder face of eccentric otch 35 along the direction of arrow indication among Fig. 2.As a result, move on to when cam 36 near second sidewall 35b of eccentric otch 35 after the position (as shown in Figure 2), moment just can be delivered on the clutch hub 13 from internal gear 14.So, clutch hub 13 according to the operation of Kick-start device to arrow z(Fig. 1) shown in direction move, thereby press flange 33 is pressed onto on the friction plate 12 clutch is closed, make engine start.

Motor is in case after the starting, the power that motor produced is from passing on the clutch hub 13 from crankshaft 2 by clutch casing 10, and therefore, just in the revolution of the direction shown in the arrow Y, its rotating speed is higher than the speed of internal gear 14 to clutch hub 13.As a result, the sidewall of eccentric otch 35 abuts against with cam 36, thereby makes clutch change Change to normal moment transmit mode shown in Figure 3 from shown in Figure 2 moving.

The centrifugal clutch C of the present invention of the basic structure of being said above having is characterized in that being equipped with shock absorber between internal gear 14 and wheel hub 13, as shown in Figure 2.

More precisely, on the inner circumferential surface of clutch hub 13, between adjacent eccentric otch 35, have buffering otch 34.These buffering otch 34 are used for holding the shock absorber 41 that is installed on internal gear 14 external peripheral surfaces, and this shock absorber system manufactures with rubber.Each shock absorber 41 all has L shaped shape, and is a buffer portion 41a at its free end.As can see from Figure 4, buffer portion 41a, has just contacted with the opposing sidewalls 34a of buffering otch 34 with before first sidewall 35a of eccentric otch 35 contacts at cam 36.Under normal transmission of torque state, buffer portion 41 produces enough resiliently deformables, thereby cam 36 can be close to mutually with first sidewall 35a of corresponding eccentric otch 35, as shown in Figure 3.

When power transfer device is in neutral position and makes the race of engine, power is sent on the clutch- plate 11,23,25, as shown in Figure 1 from crankshaft 2 by clutch casing 10, and this moment clutch output terminal, comprise that friction plate 12 and first power output gear 37 but do not produce revolution.

But, rubbing action that causes during owing to clutch- plate 11,23,25 revolutions and the engine crankshaft rotating speed of saying owing to the front have fluctuation, and cam 36 will back and forth move at both direction in eccentric otch 35.But, according to the present invention, at cam 36 with before the opposing sidewalls 35a of eccentric otch 35 contacts, shock absorber 41 on the internal gear 14 leans on last with the opposing sidewalls 34a that cushions otch 34, (as shown in Figure 4) buffer portion 41a produces resiliently deformable, and its deformation extent is between the degree shown in Fig. 4 and Fig. 3.Therefore, cam 36 has been avoided with the phenomenon of the frequent collision of sidewall 35a of eccentric otch 35, because the buffer function that resiliently deformable produced of shock absorber 41 can prevent to collide the caused vibration sound.

As can be seen from Figure 1, the outer peripheral part 11a of clutch-plate 11, just that part that cooperates with corresponding boss 22 is done thicklyer, its thickness is about radially three times by the thickness of lining part, so just formed one and impelled heat conducting part, it has strengthened the area of contact between the boss 22 on clutch-plate 11 and the clutch casing 10.Clutch-plate 11 is to manufacture with the aluminum or aluminum alloy of die casting.This structure is effective for any wearing and tearing that prevent clutch.Can notice, on the inner circumferential surface of internal gear 14, at the mid point of the axial direction of internal gear ball bearing 42 has been installed also substantially.This ball bearing 42 can be guaranteed the position of clutch hub 13, prevents that effectively friction plate 12 from producing the trend of inclination.

Though the present invention illustrates that according to specific situation clearly, the embodiment who is said not is whole, and various changes and improvements can be arranged.Such as, cam 36 and eccentric otch 35 can be contained in respectively on clutch hub 13 and the internal gear 14, although in the embodiment who is said, they are to be installed in respectively on internal gear 14 and the clutch hub 13.Equally, shock absorber 41 also can be installed on the clutch hub 13.

In addition, be to be further noted that the present invention also can be applied on the centrifugal clutch of the sort of pattern shown in the patent gazette Fig. 1 that says the front.

Claims (1)

1. Centrifugal clutch with clutch hub, the moment of transmission device will pass to this clutch by clutch-plate and friction plate, there is an internal gear to be connected with load, on above-mentioned internal gear and above-mentioned clutch hub, cam is housed all, so that match with the eccentric otch on above-mentioned internal gear and the above-mentioned clutch hub, each above-mentioned eccentric otch is separated by a distance at circumferencial direction, otch all has relative sidewall, corresponding cam can move between sidewall along its circumference, it is characterized in that, the shock absorber of manufacturing with elastic material all is equipped with on above-mentioned internal gear and above-mentioned wheel hub,, the effect of above-mentioned shock absorber is before the sidewall of above-mentioned cam and above-mentioned eccentric otch bumps, along with the turning power that above-mentioned clutch hub transmitted, shock absorber contacts with the corresponding part of above-mentioned internal gear and above-mentioned wheel hub earlier.

Images