CN1804418A - Non-boost automatic clutch employing inclined plane principle - Google Patents

Abstract

The invention relates to a mechanical automatic clutch without booster device, which comprises a friction matching pair, a drive axle, a driven axle as output axle, and at least two contact surfaces with inclined surfaces, as the taper friction surface and the screw key and screw slot used to generate axial pushing power. It utilizes the amplification function of inclined surface to generate enough connection power of clutch without variable booster devices and it can be automatically separated when the input rotational speed is reduced.

Description

Non-boost automatic clutch employing inclined plane principle

This is the invention about automatic clutch, belongs to the mechanical transmissioning technology field.

In the prior art, automatic clutch is the vehicle automatic clutch particularly, perhaps use hydraulic type, hydraulic type or electromagnetic type, complex structure and efficient is lower, perhaps use mechanically, efficient is higher but need power-assisted, no matter is hydraulic booster, motor vacuum servo or electromagnetism power-assisted, structure is all than complexity thereby rate of fault height and reliability is low, and volume weight is also bigger.

For addressing the above problem, the present invention proposes to utilize the automatic mechanical clutch of inclined plane principle, need not any power-assisted and can obtain enough big transmission power, be quick on the draw, simple and reliable for structure, mechanical efficiency height, the more existing automatic clutch of volume and weight have reduction significantly.

Main thought of the present invention is to utilize the inclined-plane, the part power of power input shaft is converted into automatic clutch engages and the power that separates, thereby save servomechanism.Describe in detail below in conjunction with accompanying drawing.

Fig. 1 is about obtain the principle schematic of clutch power with the taper key with helix angle;

Fig. 2 is about inserting the schematic representation that the spiral chute mode obtains the inclined-plane effect with bearing pin;

Fig. 3 is about having the centrifugal principle schematic that obtains engaging force on inclined-plane.

Among Fig. 1, be connected with screw key 11 on bearing supporting and the axially locating driving shaft 1, its helix angle is B, clutch driving plate 12 also is sleeved on the screw key 123 for the spiral chute 123 of B in the same way through helix angle, when driving shaft sees into it is turn clockwise (hereinafter to be referred as turning clockwise) from left to right from Fig. 1 left side direction of arrow, rotating speed is N1, then determine direction by the screw key rotation direction, the spiral fluted normal force P that is applied to driving disc that is determined size by the helix angle of screw key produces tangential component PT=P*COS (B) and axial thrust load PO=P*SIN (B), this axial thrust load direction is pressed to driven disc with driving disc, be to oppress driving disc to the right in Fig. 1, promotion driving disc 12 moves to right and engages with driven disc 21, driving disc and driven disc can be the disks that has friction plate on plane, form single disc clutch or multidisc clutch, it also can be the circular cone friction disk, it also can be the clutch of other form, its maximum delivered moment be under the axial force PO between driving disc and the driven disc by the maximum delivered moment of structure and friction factor decision, the computational methods of ripe known technology have been arranged, do not given unnecessary details here.When wanting clutch to separate, reduce the rotational speed N 1 of driving shaft 1, for example loosen the throttle of motor, then driven disc 21 drives the driving shaft rotation conversely under the moment of inertia effect, the normal force that spiral chute is applied to screw key is opposite with P, the axial thrust load that produces is also opposite with PO, and driving disc is moved to left this reverse axial force and driven disc breaks away from.

If driving disc and driven disc are the circular cone friction disks, as Fig. 1 illustration (half cut-away view), driving disc 12 slides on the driving shaft 1 and can move axially along driving shaft through spiral chute 123 and screw key 11, when the clockwise rotary driving of driving shaft, producing to the right axial force PO through screw key 11 and 123 pairs of driving discs of spiral chute 12 pushes away the driving disc right side with driven disc 21 and engages through cone of friction, driven disc 21 drives driven axle 2 rotations (driven disc and driven axle all are axially located) through key 20, and clutch is in clutching operation.Active outer cone rubbing surface 121 on the driving disc engages with the passive internal conical surface 221 of driven disc, its average diameter is D1 and semi-cone angle is A1, friction factor is U1, axial force PO is converted to conical surface positive pressure through the amplification of semi-cone angle A1, the torque T 1=PO*D1*U1/2/ that can transmit (U1*COS (A1)+SIN (A1)), and when the driving shaft input torque be in T0, the screw key footpath when the D0, PO=T0*TAN (B)/(D0/2), obviously, want effectively to transmit T0, need make T1＞=T0, obtain the locking condition and be

D1*U1*TAN(B)-D0*(U1*COS(B)+SIN(B))＞＝0 ----(1)

Inequality (1) is when being met, the axial force PO that T0 produces through spiral chute just can not be less than T0 to the torque T 1 of driven axle 2 in 121 generations of active outer cone rubbing surface, the automatic clutch secure ratcs can positive engagement transmit the big or little moment of torsion that driving shaft transmits.

When the needs clutch separation, can lower the input speed N1 of driving shaft 1, for example loosen engine throttle and make it to be in idle position, the rotary inertia that makes driven axle be connected with driven disc tends to drive driving disc, spiral chute 123 just is inclined to the screw key 11 that drives driving shaft 1 on the driving disc, so normal force and P that spiral chute is subjected to are reverse, and axial force is also just reverse with PO, this reverse axial force can be drawn back driving disc 12 with driven disc 21 left like a cork and separate, and clutch promptly separates automatically.

In order to transmit bigger moment of torsion, reduce the specific pressure on the cone of friction, a plurality of cones of friction that can be provided with coaxial line increase total cone of friction bonding area, for example among Fig. 1, just set up the cone of friction of 2 coaxial lines, except that active outer cone rubbing surface 121 can be with passive female cone rubbing surface 221 engages, active female cone rubbing surface 122 on the driving disc also engages with the passive outer cone rubbing surface 222 of coaxial line on the driven disc, its average diameter is D2, friction factor is U2, semi-cone angle is A2, and relevant calculation will have the related parameter substitution to get final product with reference to formula (1) etc.Two pairs of taper friction pairs have so just been constituted.Make two pairs or many can both positive engagement to taper friction pair, except that requiring certain machining accuracy, each of driving disc and driven disc ground running-in in pairs to smearing lapping machine on the taper friction pair earlier, eliminates error, and each that obtains at last coaxial line ground simultaneously fitting fully is to taper friction pair.Each semi-cone angle to taper friction pair can equate also can be unequal, be in order to obtain the balanced and equilibrium of dispelling the heat of desirable bond stress order and load specific pressure when unequal, and obtain rational performance parameter distribution, at this moment, unless special consideration is arranged, generally should make average diameter bigger the semi-cone angle of taper friction pair less than the taper friction pair of average diameter less than it, for example two pairs of taper friction pairs among Fig. 1 are not if semi-cone angle waits, then semi-cone angle A1 should be less than semi-cone angle A2.

The using process of inclined-plane of the present invention automatic clutch, with vehicle with being example.

Embodiment 1: the inclined-plane automatic clutch that is used for the use taper friction pair of vehicle, as shown in Figure 1, the direct sending and receiving motivation of driving shaft output shaft, driven axle 2 connects transmission input shaft, place the shift fork that links with speed change lever one gearshift mechanism in the ring groove 124 on the driving disc, can axially move to left or move to right with the slight moving driving disc of trying hard to recommend.When wanting automatic clutch to be in the disengaging configuration, shift fork drives driving disc and moves left to the left end disengaging configuration; When needs insert certain shelves for example 1 grade the time from neutral gear, speed changer inserts 1 grade of rear derailleur interlock shift fork from neutral gear and pushes away with driven disc and engage with being about to the driving disc 12 slight right sides, because the inclined-plane clutch is to make the locking condition that satisfies formula (1), the friction torque that produces makes spiral chute 123 be subjected to screw key 11 immediately and drives the axial thrust load that produces, this axial thrust load has strengthened the engage torque of taper friction pair, so finish the engaging process that the moment of torsion of positive feedback is set up, 1 grade of joint in moment.When the needs gear shift, for example change 3 grades from 2 grades, process is: the pine tar door reduces the driving shaft rotating speed, as above-mentioned, the rotary inertia of the vehicle inertia equivalence that driven axle connects makes the anti-screw keys 11 that drive of spiral chute 123 produce and make the driving disc axial force of separating that moves to left that clutch is separated automatically, speed changer (through the synchronizer effect) is thrown off 2 grades and is changed to 3 grades, gearshift mechanism pushes away driving disc through shift fork with the slight right side of ring groove 124 interlocks and contacts with driven disc, sets up engage torque immediately by above-mentioned positive feedback process equally clutch is engaged automatically.If desired from high-grade change down, for example change to 2 grades from 3 grades, action principle is the same with process, even vehicle is going up a slope, speed is lowering, but the inertia that vehicle itself has is still much larger than driving shaft to the rotary inertia of motor, and the retardation of rotating speed is greater than vehicle deceleration behind the door for the motor pine tar, and clutch still can separate automatically because of above-mentioned reverse direction actuation.At the vehicle descending, when needing motor to participate in braking, can will be connected with the chain pressure of driven axle with the clutch driving shaft of rotating speed with a lockable mechanism, this interlocking gear by existing technology aspect clutch linked device and differential mechanism linked device, have many in design and use, optional suitable person is provided with, because of belonging to prior art, do not give unnecessary details here.

When driven axle be fixed in certain or maintain static movingly, driving disc just obtained braking moment when driving disc engaged with driven disc, clutch becomes corresponding actuator, can be with the auxiliary shifting of transmission of realizing of break mode.The various automatic transmission that in 20041006886 " automatic speed changing of vehicle and passing abilitys thereof ", propose of the inventor for example, all internal gears that need brake can be braked with the break that inclined-plane of the present invention clutch constitutes, the internal gear that is braked is equivalent to driving shaft, initiatively friction cone and internal gear one are stretched out from the internal gear side, the friction cone of driven disc then is connected with housing with spiral chute through screw key, the locking condition that related parameter coincidence formula (1) is arranged, then light axial moves main passive friction cone and makes it contact and just can set up braking moment through positive feedback process internal gear is braked, which internal gear is braked, which just enters the work engagement to internal gear pair, and which shelves speed changer has just correspondingly hung up.

Can pressure or draught spring be set at an axial end of driving disc, give spring force that tends to engage of driving disc or give spring force that tends to separate of driving disc, make clutch be in normal jointing state or normal separated state, play its functions peculiar, for example make gearshift mechanism unidirectional to acting as of driving disc ring groove 124, for example spring makes clutch driving plate be in slightly the state that compresses to driven disc (among Fig. 1 to the right), make clutch be in normal jointing state, then gearshift mechanism just cooperates the action of pine tar door that clutch is temporarily separated when the gear shift to the effect of clutch.

Screw key on the driving shaft can obtain with milling the corresponding spiral fluted method of system, and the spiral chute on the driving disc endoporus can be inserted system with the slotting machine of the helical guideway of being furnished with suitable helical pitch.

When driving disc 12 endoporus spiral chutes are difficult for making, perhaps, can replace screw key and spiral chute pair with the method for on spiral chute, inserting bearing pin shown in Figure 2 in order to make driving disc axially movable resistance on driving shaft littler to reduce gearshift mechanism interlock resistance.Among Fig. 2, on driving shaft 1, mill out rotation direction and helix angle for requiring, the spiral chute 110 that width is fit to, and installing bearing pin 112 (method of installing can cooperate compression spring 113 and nut 114 bearing pin is tightened on the radial hole of correct position of driving disc endoporus with the boss on the bearing pin) on driving disc 12 endoporus, in order to reduce surface friction drag, can also make at bearing set on the bearing pin 111 and be rolling friction between the sidewall of bearing top circle and spiral chute 110, like this, when driving, driving shaft rotates, its spiral chute rotation direction decision driving shaft spiral chute gives bearing pin 112 and gives the axial force that driving disc compresses to driven disc through bearing pin 112, and other mechanism and calculating are with above-mentioned.Spiral chute should be the balanced symmetrical distribution of bull on the driving shaft, also corresponding balanced symmetrical distribution of the bearing pin that installs on the driving disc endoporus, make the suffered axial force equal and opposite in direction of each bearing pin and on driving disc endoporus circumference equiblibrium mass distribution, the turning torque that can not produce on the axial plane increase to promote the axially movable resistance of driving disc.

Above-mentioned is that screw key and spiral chute are located at driving shaft and driving disc, if screw key and spiral chute are located at driven axle and driven disc, and with driving shaft and driving disc positioning and fixing in the axial direction, the reaction axial thrust load that driven axle imposed on driven disc through screw key and spiral chute when screw key and spiral fluted rotation direction were set to driven disc and drive driven axle on driven axle and the driven disc is pressed to driving disc with driven disc to be made it to engage, its computational methods so equally can obtain above-mentioned automatic joint and the effectiveness of separating automatically still as described above.

When the rotary inertia of driving disc designs greatly, thereby the moment that driving shaft driving driving disc quickens is enough to make helical spline promotion driving disc to move axially presses to the positive feedback effect engaging clutch that driven disc is set up carry-over moment, booster engine rotating speed this moment engaging clutch automatically just, and, the driving disc that rotary inertia is bigger also can substitute the flywheel of motor, thereby the fly wheel system of economization motor, this clutch device is in the position of the former flywheel of engine interior, just become the motor that has automatic clutch, can make compact structure with the speed changer one.

Above-mentioned screw key and spiral chute are a kind of of inclined-plane, if use other its axis and driving shaft axis to have taper key, the skewed slot of angle, also can play the effect of same generation axial thrust load pressing friction dish, conveniently decide on technology.The engaging process of oblique plane type automatic clutch is the process of setting up through the friction torque of positive feedback; therefore very soft; also can have the protective action that overload is skidded automatically, can constitute high transmission efficiency function admirable gear type automatic transmission simple and compact for structure.

Utilize the inclined-plane that the another kind of the principle of the servomechanism of the amplification economization clutch of power is taken the form of the centrifugal tyep automatic clutch on tool inclined-plane, principle can be referring to Fig. 3.

Input shaft 30 rotates with input speed N1, in its end radial direction through hole 31 shape is housed, size and quality equate that fully centrifugal 32 and 33 of symmetry distributes symmetrically, the two is strained by draught spring 34, when input shaft rotating speed N1 is enough high, centrifugal pulling force that overcomes draught spring under centrifugal action moves outside radially, the semi-cone angle of the monosymmetric inclined-plane of its outer rim---circular cone rubbing surface is C, C is generally 4 and spends between 15 degree, internal conical surface frictional engagement with output sleeve 4, positive pressure=centrifugal force on the rubbing surface/SIN (C), centrifugal force is exaggerated, the friction torque that produces drives output sleeve 4 and drives the output shaft 43 that coaxial line is connected through key again, moment=centrifugal force * friction factor * rubbing surface mean radius/SIN (C) that rubbing surface transmits.Because semi-cone angle is the amplification of the inclined-plane of C to centrifugal force, can obtain enough joint friction torque for centrifugal of less quality and size, and can save servomechanism.The effect of draught spring, centrifugal centrifugal force is less than or equal to spring tension thereby centrifugal and can outwards move and the output sleeve frictional engagement in the footpath when being to make engine idle.Fig. 3 shows a pair of centrifugal of symmetrical distribution, and many centrifugal to distribution symmetrically and evenly can also be set, to increase centrifugal force and to keep dynamic balancing.

Prior art is square direct ratio of its transmitting torque and rotating speed and the cube direct ratio of transmitted power and rotating speed to the conclusion of centrifugal friction clutch, and the clutch that therefore is not suitable as transmission for vehicles uses.This conclusion will be made a concrete analysis of, and solves the problem that it runs into.At first, motor is also very little at the moment of torsion of the rotating speed of a little higher than idling, is operated in this rotating speed, requires the moment of torsion of clutch transmits little, and oblique plane type centrifugal clutch of the present invention can satisfy this transmitting torque under the amplification of inclined-plane to centrifugal force; Secondly, when rotating speed is very high, for example 3000 per minutes change, centrifugal force is very big, the permitted value that might surpass the specific pressure allowable of rubbing surface, for addressing this problem, can make half rubbing surface of output sleeve axially movable, cooperate spring---elastic material, to excessive centrifugal force unloading, for example in Fig. 3, to make and (to be connected with transmitting torque with output sleeve 4 coaxial line ground along the axially movable of output sleeve 4 with the right friction ring 40 of centrifugal right side circular cone rubbing surface contact through key 41, output sleeve is corresponding make the machinery assembling to satisfy assembly relation), be provided with elastic material ring 421 at right friction ring right-hand member, its right-hand member is output axle sleeve to be stoped and can not move to right, when the input shaft rotating speed very high, when centrifugal centrifugal force is very big, the right friction ring of centrifugal (32) extruding pushes the elastic material ring to the right, centrifugal is continued to obtain a displacement to the direction that radius increases, extruding diametrically is located at the top ring 422 of the elastic material on centrifugal outer rim top, the elastic material that part centrifugal force is encircled by the top sponges, form new force system in equilibrium, so just reduced the positive pressure on the rubbing surface, make it not because of centrifugal force excessive so that bring possible damage when very big to rubbing surface.

But in general, the allowable value that the specific pressure allowable of centrifugal both sides rubbing surface provides on can be far above existing handbook under the condition of the present invention, this is because generally be the process that is in clutch when between two rubbing surfaces slide relative being arranged, rotating speed is not high at this moment, centrifugal force is little, though and rotating speed when very high centrifugal force is very big on the rubbing surface specific pressure high, but two bevel friction face positive engagement wedgings, do not have the possibility of slip each other, therefore this static relatively rubbing surface can use very high specific pressure allowable.

Like this, the inclined-plane centrifugal friction clutch engages automatically when rotating speed raises, and rotating speed when reducing clutch separate automatically, the control engine throttle just can be used the corresponding gear shift of speed changer.

The automatic clutch that has the inclined-plane that the present invention proposes can be brought up the automatic transmission of high transmission efficiency simple and compact for structure, save the existing manpower that needs and trample plate clutch with complicated servomechanism, also save the very low baroque eddy current torque converter of the used efficient of existing automatic transmission.

Claims (6)

1 one kinds of automatic mechanical clutchs that need not servomechanism, it is that input shaft and driven axle are output shaft that frictional engagement pair, driving shaft are arranged, it is characterized in that, on the transmission of torque route, has the bevelled surface of contact of 2 subbands at least, these inclined-planes amplify the engaging force of clutch, thereby save servomechanism.

2 automatic clutches according to claim 1, it is characterized in that, at least being provided with a pair of circular cone friction disk pair between driving shaft and driven axle engages as described inclined-plane or separates driving shaft and driven axle, the semi-cone angle of taper friction pair is that 3 degree are between 15 degree, have the taper key of angle or skewed slot as described another secondary inclined-plane having its axis and driving shaft axis on the driving shaft or on the driven axle, but be enclosed within the corresponding skewed slot of circular cone friction disk endoporus axial slip, on taper key or the bearing pin, taper key, the direction of skewed slot is that torque is at taper key when driving shaft drives driven axle, the axial thrust load that skewed slot produces pushes away two circular cone friction disks closely and compresses.

3 automatic clutches according to claim 2, it is characterized in that, described taper key, skewed slot are screw key, spiral chute, to obtain processing technology easily, the product of the tangential force absolute value that the tangent of its helix angle B and torque produce at screw key, spiral chute equals the absolute value of axial thrust load, and the direction of axial thrust load compresses mutually for promoting the friction disk parafacies when driving shaft drives operating mode.

4 automatic clutches according to claim 3, it is characterized in that, each parameter meets following locking condition: footpath D0* (U1*COS (B)+SIN (B))＞=0 in circular cone rubbing surface average diameter D1* friction factor U1*TAN (helix angle B)-screw key or the spiral chute, when this condition expression met, the axial thrust load pressing friction dish transmission that automatic clutch can rely on oblique key, groove to produce was not less than the moment of torsion that produces axial thrust load.

5 automatic clutches according to claim 1, it is characterized in that, also have centrifugal, draught spring and can with the output sleeve of centrifugal rubbing contact, the bevel friction face that centrifugal outer rim both sides have is described two inclined-planes, driving shaft drives centrifugal rotation, when rotating speed is enough high, centrifugal pulling force footpath that overcomes draught spring under centrifugal action outwards moved and the output sleeve frictional engagement, the amplification on centrifugal inclined-plane makes positive pressure=centrifugal force/SIN (the semi-cone angle C on inclined-plane) on the rubbing surface, much larger than centrifugal force.

6 automatic clutches according to claim 5, it is characterized in that, on output sleeve, also have one can move axially the also friction ring 40 of energy transmitting torque, domed end is provided with the top ring 422 that elastic material is made outside centrifugal, when rotating speed when very high centrifugal force is excessive, the centrifugal removable friction ring 40 of compressing moves axially compressing elastic material ring 421, centrifugal outer domed end oppressed the elastic material that the top is encircled simultaneously, make the top ring share a part of centrifugal force, prevent that rubbing surface from damaging because of centrifugal force is excessive.

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