JPH1182627A - Torque fluctuation reduction device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a durable and effective use of centrifugal force by suppressing the generation of vibration and sound with small impact. A driving member (3) fixed to a crankshaft (1), a driven member (7) bearing-supported by the driving member (3), a first gear (11), a second gear (19), The centrifugal clutch mechanism 41 includes a sub flywheel 23 connected via a three-gear 25 and a centrifugal clutch mechanism 41. The centrifugal clutch mechanism 41 elastically deforms radially outward of the crankshaft 1 to engage and disengage with the elastic plate 29. A plurality of pairs of masses 31 that elastically deform the elastic plate 29 by centrifugal force are provided between the driving-side member 3 and the driven-side member 7 in the circumferential direction, and the masses 31 are selectively different in weight. It is characterized by the following.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque fluctuation reducing device attached to an end of a crankshaft.

[0002]

2. Description of the Related Art This type of torque fluctuation reducing device reduces the fluctuation of the rotation of a crankshaft due to the fluctuation of the torque of an engine and attenuates the torsional vibration of the crankshaft so that the power can be smoothly transmitted to an output shaft. For example, there are those shown in FIGS. 8 and 9 described in JP-A-5-18440 and those shown in FIG. 10 described in JP-A-8-261291.

FIG. 8 shows a main flywheel 101 and a sub flywheel 103. The main flywheel 101 is fixed to a crankshaft 105, and the main flywheel 101 and the sub flywheel 103 are connected to a torsion damper 107. A stopper mechanism 109 is provided between the flywheels 101 and 103 to restrict the relative rotation between the flywheels 101 and 103 within a predetermined angle.
A centrifugal clutch mechanism 111 that integrates the two only when 5 is equal to or less than a predetermined number of revolutions is provided.

[0004] The centrifugal clutch mechanism 111 has a mass body 113 and a spring 115 as shown in FIG. 9.
Supported in a receiving recess 117 formed in the inner peripheral surface of the side.
The convex portion 119 of the mass body 113 is generated by the urging force of the spring 115.
Are engaged with a concave portion 121 formed on the outer peripheral surface on the side of the sub flywheel 103.

When the rotation of the crankshaft 105 exceeds a predetermined number of revolutions, the mass body 113 moves into the accommodation recess 117 against the urging force of the spring 115 by centrifugal force, and the projection 119 is disengaged from the recess 121. Is cut off. Conversely, if the rotation of the crankshaft 105 falls below a predetermined number of revolutions, the urging force of the spring 115 overcomes the centrifugal force and urges the mass body 113 to move.
9 into the recess 121 and the main flywheel 10
1 and the sub flywheel 103 can be connected.

In FIG. 10, a centrifugal clutch mechanism 111 provided between the main flywheel 101 and the sub flywheel 103 is as follows. That is, a friction plate 123 having a friction surface in a direction intersecting with the axis of the crankshaft 105 is provided on the main flywheel 101 side, and a contact surface 125 with which the friction plate 123 contacts the sub flywheel 103 is formed. A disc spring 129 to which a mass body 127 is fixed is provided between the main flywheel 101 and the friction plate 123.

When the rotation of the crankshaft 105 falls below a predetermined number of revolutions, the disc spring 129 keeps its original shape and the friction plate 123 is brought into contact with the contact surface 125 by its spring force.
And the main flywheel 101 and the sub flywheel 103 are connected. When the rotation of the crankshaft 105 exceeds a predetermined rotation speed, the disc spring 1
The rotational centrifugal force by the 29 mass bodies 127 becomes large,
The disc spring 129 moves away from the sub flywheel 103 against its spring force, and accordingly, the friction plate 1
23 is separated from the contact surface 125, and the clutch is disengaged.

[0008]

However, FIG.
In the conventional example shown in FIG. 9, since the centrifugal clutch mechanism 111 has an engagement structure between the convex portion 119 and the concave portion 121, even if the rotation of the crankshaft 105 exceeds a predetermined number of revolutions during sudden acceleration or the like, the convex portion 119 and the concave portion The engagement between the sub flywheel 1 and the sub flywheel 1
There is a risk that the 03 side will be accompanied by high rotation.

Further, when the rotation of the crankshaft 105 shifts from a state where it exceeds the predetermined number of rotations to a state where it falls below the predetermined number of rotations, the rotation direction is restricted as soon as the projections 119 are engaged with the recesses 121, so that the impact becomes large and the vibration increases. In addition to the problem of noise and sound, durability may be impaired.

[0010] On the other hand, in FIG. 10, since the friction plate 123 is used, the above-mentioned problem is less likely to occur, but the direction of the centrifugal force acting on the mass body 127 is orthogonal to the direction of generating the elastic force of the disc spring 129. In such a state, there is a problem that the centrifugal force cannot be effectively applied, and the weight of the mass body 127 increases. Further, since the engagement between the two flywheels 101 and 103 is only frictional engagement, there is a problem that slippage is likely to occur.

Accordingly, the present invention makes it possible to reduce the weight of the mass body by effectively applying the centrifugal force of the mass body, and furthermore, the occurrence of problems such as vibration and noise is reduced even in the case of meshing engagement. It is an object of the present invention to provide a torque fluctuation reducing device that can perform the operation.

[0012]

According to a first aspect of the present invention, there is provided a driving member fixed to a crankshaft, a driven member bearing-supported by the driving member, and a driving member connected to the driven member. And a centrifugal clutch mechanism that disconnects when a predetermined rotation is exceeded between the driving side member and the driven side member. Alternatively, an elastic plate fixed to one of the driven-side members and engaged with the other, elastically deformed outwardly in a direction perpendicular to the axis of the crankshaft to be disengaged, and a centrifugal force provided on the elastic plate. A plurality of sets each including a mass body that elastically deforms the elastic plate are provided between the driving side member and the driven side member in a circumferential direction, and each of the mass bodies is selectively different in weight. .

Therefore, when the rotation speed of the crankshaft is lower than the predetermined rotation speed, the elastic plate fixed to one of the driving side member and the driven side member is engaged with the other, and the state is established in which both members are connected. Has become. When the rotation speed of the crankshaft exceeds a predetermined rotation speed, the elastic plate elastically deforms radially outward of the crankshaft due to the centrifugal force of the mass attached to the elastic plate, and the driving side member and the driven side member. And the clutch is disconnected. At this time, since the respective masses of the plurality of elastic plates provided in the circumferential direction are selectively different in weight, the elastic deformation of each elastic plate outward in the radial direction is performed by a group including the heavier mass. Then, the disengagement of the elastic plates is gradually performed among the plurality of elastic plates in the circumferential direction. Conversely, when the rotation speed of the crankshaft is lower than the predetermined rotation speed, the engagement of the elastic plates is also gradually performed between the plurality of elastic plates in the circumferential direction.

According to a second aspect of the present invention, there is provided the torque fluctuation reducing device according to the first aspect, wherein concave portions or convex portions are provided on the outer periphery of the driven-side member or the driving-side member at predetermined circumferential intervals.
The elastic plate on which the relatively heavy mass is set is provided with a convex portion or a concave portion which is engaged with the concave portion or the convex portion in the circumferential direction, and the elastic plate on which the relatively light mass is set is driven. It is characterized by being frictionally engaged on the outer periphery of the side member or the drive side member.

Therefore, in addition to the operation of the first aspect of the present invention, in the elastic plate having a relatively heavy mass body, the convex portion or the concave portion is engaged with the concave portion or the convex portion of the driven member or the driving member. As a result, a reaction force is generated between the convex portion and the concave portion that engage with each other, and the elastic plate having the light mass body is frictionally engaged with the driven side member or the driving side member to generate a frictional force therebetween. I do. Therefore, the reaction force between the convex portion and the concave portion is reduced, and the engagement and disengagement of the elastic plate can be performed smoothly.

Further, when the crankshaft is going to fall below a predetermined number of revolutions, the elastic plate having a relatively light mass is frictionally engaged with the outer periphery of the driving member or the driven member first. The rotation of the driving side member and the driven side member can be synchronized, and then the convex portion or the concave portion of the elastic plate on which the heavy mass is set becomes the concave portion or the convex portion of the driven side member or the driving side member. Can be engaged.

According to a third aspect of the present invention, there is provided the torque fluctuation reducing device according to the second aspect, wherein the flexural rigidity of the elastic plate having the concave portion or the convex portion is smaller than the flexural rigidity of the other elastic plates. And

Therefore, in addition to the effect of the invention of claim 2, when the crankshaft falls below a predetermined number of revolutions, a relatively light mass body having high bending rigidity can be frictionally engaged from the set elastic plate. The rotation of the driving member and the driven member can be reliably synchronized before the elastic plate having a relatively heavy mass body is meshed and engaged by the protrusion or the recess.

According to a fourth aspect of the present invention, there is provided the torque fluctuation reducing device according to the second or third aspect, wherein an engaging portion is provided between the elastic plates so as to mutually engage inward and outward in a direction perpendicular to the crankshaft axis. The mass body of the elastic plate engaged from the radial outside,
It is characterized in that it is set heavier than the mass body of the elastic plate engaged from the radial inside.

Therefore, the centrifugal force of the elastic plate having the relatively light mass can be transmitted to the elastic plate having the heavy mass, and the elastic plate having the heavy mass engaged with the convex and concave portions. Can be smoothly performed.

According to a fifth aspect of the present invention, there is provided the torque fluctuation reducing device according to any one of the first to fourth aspects, wherein the elastic plate is formed of two layers of metal material in a direction perpendicular to the crankshaft axis. The expansion coefficient of the outer layer is set larger than that of the inner layer in the radial direction.

Therefore, in addition to the function of any one of the first to fourth aspects of the present invention, when the heat generated by the friction between the driving side member or the driven side member and the elastic plate exceeds a predetermined value, the elastic plate becomes It can be deformed and moved in a direction away from the driving side member or the driven side member.

According to a sixth aspect of the present invention, there is provided a driving member fixed to a crankshaft, a driven member supported by the driving member, and a sub flywheel connected to the driven member. In a torque fluctuation reduction device including a centrifugal clutch mechanism that disconnects when the rotation exceeds a predetermined rotation between the drive-side member and the driven-side member, the centrifugal clutch mechanism includes the drive-side member or the driven-side member. A female screw portion provided on the outer peripheral side and having a central axis in the crankshaft axial direction, a male screw member screwed to the female screw portion, and frictionally engaged with the driven member or the drive member provided at one end of the male screw member A possible friction member, and the male screw member interposed between the male screw member and the driving member or the driven member biases the male screw member to one side with respect to the female screw portion to rotate the friction member to the driven member or the driving member. side An urging member to be frictionally engaged with the arm member; an arm portion having one end fixed to the other end of the male screw member and extending in a direction perpendicular to the crankshaft axis; and a mass body fixed to the other end of the arm portion. It is characterized by.

Accordingly, the centrifugal force acting on the mass body is converted into torque by the arm portion, and the torque is increased to the axial force of the externally threaded member by utilizing the leverage of the screw, so that the friction member is driven or driven. It can be frictionally engaged with the drive side member.

According to a seventh aspect of the present invention, there is provided the torque fluctuation reducing device according to the sixth aspect, wherein the centrifugal clutch mechanism includes the female screw portion, the male screw member, the friction member, the urging member, the arm portion, and the mass body. A plurality of sets are provided between the driving-side member and the driven-side member in the circumferential direction, and each of the mass bodies is selectively different in weight.

Therefore, in addition to the function of the invention of claim 6, since the weights are selectively different from each other, the contact timing between the plurality of friction members and the driven member or the driven member is shifted. be able to.

The invention according to claim 8 is the torque fluctuation reducing device according to claim 7, wherein the diameter of the friction member of the set having a relatively heavy mass between the respective masses is the same. The diameter of the friction member is set smaller than the diameter of the set of friction members, and the driven side member or the drive side member is provided with an engagement recess having a diameter between the two diameters of the friction member. I do.

Accordingly, a set of friction members having a relatively heavy mass body can be engaged with the engagement recess of the driven member or the driving member.

According to a ninth aspect of the present invention, there is provided the torque fluctuation reducing device according to the seventh aspect, wherein a protrusion or a recess is provided on the friction member having a relatively heavy mass body among the mass bodies, and The drive-side member or the drive-side member is provided with a concave portion or a convex portion for engaging the convex portion or the concave portion.

Therefore, in addition to the function of the invention of claim 7, it is possible to engage a set of friction members having a relatively heavy mass with the driven side member or the driving side member via the convex or concave portion. it can.

According to a tenth aspect of the present invention, there is provided a driving member fixed to a crankshaft, a driven member supported by the driving member, and a sub flywheel connected to the driven member. In a torque fluctuation reduction device comprising a centrifugal clutch mechanism that disconnects when the rotation exceeds a predetermined rotation between the driving-side member and the driven-side member, the centrifugal clutch mechanism has a central axis in a direction perpendicular to a crankshaft axis. A first cylinder and a second cylinder having a central axis in the axial direction of the crankshaft; and a first liquid chamber provided in the first cylinder to form a first liquid chamber and to move outward by a centrifugal force in a direction perpendicular to the crankshaft axis. A first piston that expands the liquid chamber and a second piston that is provided in the second cylinder and that communicates with the first liquid chamber and that forms a second liquid chamber and that can be frictionally engaged with the driven member or the driving member. Tons, characterized in that said second piston becomes more and a biasing member engaged driven-side member or the friction and urged toward the drive-side member.

Therefore, when the rotation speed of the crankshaft is lower than the predetermined rotation speed, the second force is generated by the urging force of the urging member.
The piston can make frictional contact with the driven or driven member. When the number of revolutions of the crankshaft exceeds a predetermined number of revolutions, the first piston moves by the centrifugal force acting on the first piston and enlarges the first liquid chamber. Due to this enlargement, the liquid in the second liquid chamber moves to the first liquid chamber, the second piston moves against the urging force of the urging member, and releases the frictional engagement with the driven member or the driving member. be able to.

That is, the change and increase in the direction of the centrifugal force acting on the mass body can be achieved by using the fluid.

An eleventh aspect of the present invention is the torque fluctuation reducing device according to the tenth aspect, wherein the pressure receiving area of the first piston is smaller than the pressure receiving area of the second piston.

Therefore, in addition to the function of the tenth aspect,
By moving the first piston, a larger moving force can be applied to the second piston.

A twelfth aspect of the present invention is the torque fluctuation reducing device according to any of the first to eleventh aspects, wherein the centrifugal clutch mechanism is supported by the driven member.

Accordingly, in addition to the effects of the first to eleventh aspects of the present invention, it is possible to suppress imbalance during high rotation of the crankshaft.

[0038]

According to the first aspect of the present invention, the detachment of the driving-side member and the driven-side member is performed with a sufficient rotation speed range, so that the detachment can be performed more smoothly.

According to a second aspect of the present invention, in addition to the effect of the first aspect, the elastic plate having no convex portion or concave portion is frictionally engaged with the driven member or the outer periphery of the driving member. Thus, even if a mechanism for transmitting the torque by meshing with the rotation of both is synchronized, a smooth coupling with less impact can be made possible.

According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, a smoother separation without impact becomes possible.

According to the fourth aspect of the present invention, in addition to the effects of the second or third aspect of the present invention, the departure when the load torque at the time of rapid acceleration is large is ensured, and the sub flywheel is prevented from having a high rotational speed. Becomes possible.

According to the fifth aspect of the invention, in addition to the effects of any one of the first to fourth aspects, the heat generated by the friction between the driven side member or the driving side member and the elastic plate becomes abnormally large. In this case, the elastic plate moves in a direction away from the driven side member or the driving side member, so that damage due to heat can be avoided.

According to the sixth aspect of the present invention, since the leverage effect of the screw is used, a compact structure can be obtained in view of the required weight of the mass body.

According to the seventh aspect of the present invention, in addition to the effect of the sixth aspect of the present invention, since the masses are selectively different in weight, the engagement and disengagement can be performed with less impact.

According to the eighth aspect of the invention, in addition to the effect of the seventh aspect of the invention, more secure coupling can be performed.

According to the ninth aspect of the invention, in addition to the effect of the seventh aspect of the present invention, more reliable coupling can be performed by the convex or concave portion.

According to the tenth aspect, conversion of the direction of the centrifugal force can be achieved with a simple structure. A mechanism for synchronizing the rotation of the driving side member and the driven side member by a frictional force so that no shock is generated when the driving side member and the driven side member are coupled in the rotation direction, so that it is smooth. Can be achieved.

According to the eleventh aspect, in addition to the effect of the tenth aspect, it is possible to increase the urging force of the urging member while maintaining a compact structure with a simple structure.

According to the twelfth aspect of the present invention, in addition to the effects of any one of the first to eleventh aspects, it is possible to avoid the occurrence of vibration due to imbalance when the crankshaft rotates at a high speed.

[0050]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 is a schematic sectional view of a torque fluctuation reducing device according to a first embodiment of the present invention. In FIG. 1, an upper half from a rotation center line is shown. FIG.
As described above, the drive side member 3 is fixed to the crankshaft 1 with bolts (not shown). The main flywheel 5 is attached to the drive side member 3. The main flywheel 5 is connected to the transmission via a clutch mechanism (not shown). A driven side member 7 is supported on the outer periphery of the driving side member 3 via a radial bearing 9. A first gear 11 is provided on the peripheral surface of the driven member 7.

A support portion 17 is provided on a support frame member 15 fixed to the cylinder block 13, and a second gear 19 meshing with the first gear 11 is rotatably supported. A sub flywheel 23 is rotatably supported on the outer peripheral side of the support portion 17 via a radial bearing 21. On the inner periphery of the sub flywheel 23,
A third gear 25 meshing with the second gear 19 is provided.

A centrifugal clutch mechanism 27 is provided between the driving side member 3 and the driven side member 7 so as to disconnect when the crankshaft 1 exceeds a predetermined number of revolutions. The centrifugal clutch mechanism 27 includes a plurality of sets each including an elastic plate 29 and a mass body 31 between the drive side member 3 and the drive side member 7 in the circumferential direction.

One end of the elastic plate 29 is fixed to the outermost peripheral side of the driving side member 3 and is supported in a cantilever manner.
A plurality of the elastic plates 29 are provided in the circumferential direction of the driving side member 3 as shown in FIG. The mass body 31 is fixed to the outer peripheral surface of each elastic plate 29, and is set so as to selectively have different weights.

That is, as shown in FIG. 2 or FIG. 3, the mass body 31 is provided with eight mass bodies 3 corresponding to the elastic plate 29.
1a and 31b, which are fixed to the outer peripheral surface of the elastic plate 29. The mass bodies 31a and 31b are provided alternately, and the mass body 31a is set heavier than the mass body 31b.

A ring-shaped contact member 33 is provided on the outermost periphery of the driven side member 7. Each elastic plate 29 is configured to engage with the contact member 33.

In the present embodiment, as shown in FIG. 4, which is an enlarged sectional view of the portion IV in FIG. 3, an elastic plate 29a on which a heavy mass body 31a is set is engaged with the contact member 33. The elastic plate 29b provided with the light mass body 31b is structured to frictionally engage with the outer peripheral surface of the contact member 33. On the outer periphery of the contact member 33 of the driven side member 7, a plurality of concave portions 35 are provided at the same pitch as the elastic plate 29a. The recess 35 is provided with an engagement surface 35a extending in the radial direction. The one elastic plate 29a is provided with a convex portion 37 on the inner peripheral side. The projection 37 has an engaged surface 37a that engages with the engagement surface 35a. Note that a configuration in which a convex portion is provided on the contact member 33 side and a concave portion is provided on the elastic plate 29a side may be employed.

The elastic plates 29a, 29b are provided with engaging portions 39a, 39b mutually inwardly and outwardly in the direction perpendicular to the axis of the crankshaft. Engaging portions 39a, 39
b is formed in a stepped shape and is a structure that fits each other,
The engaging portion 3 on the elastic plate 29a side where the heavy mass body 31a is set.
9a is configured to engage with the engaging portion 39b on the elastic plate 29b side on which the light mass body 31b is set from the radial outside. Therefore, the elastic plate 29a engaged from the radially outer side
Elastic plate 29b which engages the mass body 31a from the inside in the radial direction
Is configured to be heavier than the mass body 31b.

The flexural rigidity of the elastic plate 29a having the convex portion 37 is set smaller than the flexural rigidities of the other elastic plates 29b. Further, each elastic plate 29a, 29b
Although not explicitly shown, is formed of two layers of metal material in the direction perpendicular to the crankshaft axis, and has a larger coefficient of thermal expansion of the outer layer than the radially inner layer.

With this configuration, when the crankshaft 1 is lower than the predetermined number of revolutions, the elastic plate 29a
7 engages with the concave portion 35 of the contact member 33 of the driven side member 7, and the elastic plate 29 b frictionally engages with the contact member 33. Accordingly, the rotation of the crankshaft 1 is controlled by the driving member 3, the centrifugal clutch mechanism 27, the driven member 7,
The power is also transmitted to the sub flywheel 23 via the first gear 11, the second gear 19, and the third gear 25, and the sub flywheel 23 rotates in a direction opposite to the crankshaft 1.
As a result, the inertial force of the flywheel device accompanying the rotation of the crankshaft 1 can be obtained by adding the mass of the main flywheel 5 and the mass of the sub flywheel 23.

When the rotation of the crankshaft 1 exceeds a predetermined number of revolutions, the elastic plates 29a and 29b are elastically deformed radially outward of the crankshaft 1 by the centrifugal force θ acting on the mass bodies 31a and 31b. The engagement of the contact members 33 with the contact members 33 is released, the connection between the driving member 3 and the driven member 7 is disconnected, and the clutch is disengaged. For this reason, the sub flywheel 23 is separated from the rotation of the main flywheel 5, and the inertia of the flywheel device associated with the rotation of the crankshaft 1 is small only for the main flywheel 5.

Each of the elastic plates 29a and 29b is
When elastically deformed by centrifugal force acting on a and 31b,
Since the heavy mass body 31a advances elastic deformation first, the elastic plates 29a and 29b do not engage and disengage at once,
The engagement and disengagement is gradually performed between the elastic plates 29a and 29b,
Smooth engagement and disengagement can be performed within a sufficient rotation speed range.

During acceleration, a reaction force P acting on the engaging surface 35a and the engaged surface 37a of the concave portion 35 and the convex portion 37, and a frictional force F against the contact member 33 acting on the elastic plate 29b having no convex portion. Can take charge of the load torque, and the mutual reaction force P generated on the engagement surface 35a and the engaged surface 37a is reduced by that amount, so that the meshing can be easily released even at a high load torque. And a smooth separation is possible.

The engaging portions 39 of the elastic plates 29a and 29b
Since a and 39b overlap inward and outward in the radial direction, centrifugal force on the elastic plate 29b side can also act on the elastic plate 29a side, and the meshing reaction force P on the engagement surface 35a and the engaged surface 37a can be achieved. Irrespective of this, the engagement between the concave portion 35 and the convex portion 37 can be reliably released.

Further, since the bending rigidity of the elastic plate 29a having the convex portion 37 is set smaller than that of the elastic plate 29b having no convex portion, the centrifugal force of the mass body 31a is reduced. Is easily elastically deformed, and the protrusion 37
Can be easily separated from the recess 35.

Accordingly, the convex portion 37 can be detached from the concave portion 35 very smoothly by centrifugal force, while a reliable connection between the driving side member 3 and the driven side member 7 can be obtained by the engagement structure. Moreover, the mass body 31a,
Since the direction of the centrifugal force of the elastic plate 31b and the direction of the elastic deformation of the elastic plates 29a and 29b are substantially the same, the centrifugal force can be used effectively, and the mass bodies 31a and 31b can be smoothly reduced while their size is reduced. The engagement and disengagement can be performed.

On the other hand, when the number of revolutions of the crankshaft 1 falls and falls below the predetermined number of revolutions, the elastic plate 29b of the mass body 31b, which is set relatively light, first comes into contact with the driven side member 7. The member 33 is brought into frictional contact with the member 33 so that the drive-side member 3 and the driven-side member 7 can be synchronized. Thereafter, since the convex portion 37 of the elastic body 29a having the relatively heavy mass body 31a meshes with the concave portion 35 of the contact member 33, the mutual meshing is performed extremely smoothly, and the occurrence of meshing shock and abnormal noise is largely suppressed. can do. This functions, for example, as a synchronization mechanism of a manual transmission.

Since the elastic plates 29a and 29b are made of, for example, two layers of metal material, when abnormal heat is generated due to friction between the elastic plate 29 and the driven member 7,
The elastic plates 29a and 29b move radially outward away from the contact member 33, so that damage due to heat can be avoided.

(Second Embodiment) FIGS. 5 and 6 show a second embodiment of the present invention. FIG. 5 is a sectional view corresponding to FIG.
Is an enlarged view of a main part. The components corresponding to those in the first embodiment are denoted by the same reference numerals, and the description will not be repeated.

In this embodiment, the centrifugal clutch mechanism 4
1 is a drive-side member that includes a male screw member 45 screwed into the female screw portion 43, a friction member 47 provided at one end of the male screw member 45, a biasing member 49, an arm portion 51, and a mass body 53. 3 are provided in the circumferential direction.

The female screw portion 43 is provided on a casing 55 fixed to the outermost periphery of the drive side member 3, and the male screw member 45 is screwed to the female screw portion 43. The friction member 47 has a circular cross section as shown in FIGS. 5 and 6 and is fixed to one end of the male screw member 45. Friction member 47
Sets the diameter of the friction member 47 having a relatively heavy mass among the masses 53 to be smaller than the diameter of the friction member 47 having the light mass 53 on the driven side. The member 7 has an engagement recess 57 having a diameter between the large and small diameters of the friction member 47. Therefore, the set of friction members 47 having the heavy mass is engaged with the engagement concave portion 57, and the set of friction members 47 having the light mass 53 is frictionally engaged with the front surface of the driven member 7. Become. Note that all the friction members 47 may be frictionally engaged with the driven member 7.

The urging member 49 is a spring having a spring shape, one end of which is fixed to the casing 55, the other end of which is fixed to the friction member 47, and the male screw member 45 rotates in one direction with respect to the female screw portion 43. It is energizing. With this bias, the male screw member 45 moves toward the driven member 7 side with respect to the female screw portion 43, and the friction member 47 is moved to the driven member 7.
Frictional engagement and meshing engagement.

As shown in FIGS. 5 and 6, one end of the arm portion 51 is fixed to the other end of the male screw member 45 and extends in a direction perpendicular to one axis of the crankshaft. The mass body 53 is fixed to the other end of the arm 51. Each mass 53
The pair having the small diameter friction members 47 is set relatively heavy, and the pair having the large diameter friction members 47 is set relatively light. However, it is also possible to set all the mass bodies 53 to the same weight.

In the present embodiment, the urging member 49 rotates the male screw member 45 to push the friction member 47 against the driven member 7. On the other hand, the centrifugal force acting on the mass body 53 causes the male screw member 45 to rotate in the opposite direction via the arm portion 51, and attempts to move the friction member 47 in a direction in which the engagement with the engagement recess 57 is released. Therefore, the magnitude relationship between the torque by the centrifugal force of the mass body 53 acting on the male screw member 45 and the torque by the urging member 49 changes according to the rotation speed of the crankshaft 1, and the friction member 47 can perform the clutch action. . Therefore, also in the present embodiment, the centrifugal force of the mass body 53 can be opposed to the urging force of the urging member 49, and the centrifugal force can be effectively used.

Further, the screw mechanism of the female screw portion 43 and the male screw member 45 has a function of leverage that converts the direction of action of the centrifugal force of the mass body 53 to the axial direction of the crankshaft and increases the force in that direction. Play. Accordingly, the engagement and disengagement of the friction member 47 with the driven-side member 7 can be gradually performed, and the engagement and disengagement can be achieved smoothly. Further, since the plurality of mass bodies 53 are selectively set to have different weights, the mass bodies 53 move first due to centrifugal force, and the mass bodies 53 are moved between the friction members 47 having different settings. Disengagement of the frictional engagement with the drive-side member 7 can be performed more gradually, so that smoother disengagement is possible. That is, also in the present embodiment, when the rotation speed of the crankshaft 1 exceeds the predetermined rotation speed, the heavy mass body 53 starts moving by centrifugal force first,
The corresponding friction member 47 is disengaged from the engagement concave portion 57, and the light mass 53 moves by centrifugal force with a delay, and the corresponding friction member 47 releases frictional contact with the driven side member 7.

When the crankshaft 1 falls below the predetermined number of revolutions, first, the friction member 47 on the side on which the light mass 53 is set frictionally engages with the driven member 7 to synchronize with the driving member 3. Then, the friction member 47 on the side where the heavy mass body 53 is set is engaged with the engagement recess 57, and the drive side member 3
And the driven member 7 can be connected.

Therefore, in the present embodiment, substantially the same operation and effect as those of the first embodiment can be obtained. In addition, such a structure enables a compact structure. Further, since a mechanism for amplifying the centrifugal force by a screw lever action is provided, the weight of the mass body 53 for generating the centrifugal force can be reduced, and vibration due to rotational imbalance particularly in a high rotational speed range is reduced. be able to.

In the second embodiment, a convex or concave portion is provided on the friction member 47 of the set provided with the heavy mass body 53, and the concave or convex portion for engaging the convex or concave portion with the driven member 7 is provided. It is also possible to provide them and engage them with each other.

(Third Embodiment) FIG. 7 is a sectional view corresponding to FIG. 1 according to a third embodiment. The components corresponding to those in FIG. 1 are denoted by the same reference numerals, and the description will not be repeated.

In this embodiment, the centrifugal clutch mechanism 59 is constituted by a piston cylinder mechanism. That is, a first cylinder 61 having a central axis in a direction perpendicular to one axis of the crankshaft and a second cylinder 63 having a central axis in one axis direction of the crankshaft are integrally provided on the outermost periphery of the driving side member 3.

A first piston 65 is accommodated in the first cylinder 61. The first piston 65 acts as a mass body, moves outward in a direction perpendicular to one axis of the crankshaft by centrifugal force, and expands the first liquid chamber 67.

A second piston 69 is accommodated in the second cylinder 63, and a second liquid chamber 71 communicating with the first liquid chamber 67 through a communication passage 70 is formed. An urging member 73 made of a metal spring is provided in the second cylinder 63 to urge the second piston 69 against the driven-side member 7 to make frictional contact.

The opposite side of the first piston 65 to the first liquid chamber 67 in the first cylinder 61 is an air chamber,
The second piston 69 with respect to the second liquid chamber 71 of the cylinder 63
The other side is open to the atmosphere.

Accordingly, when the crankshaft 1 is lower than the predetermined number of revolutions, the second piston 69 is frictionally engaged with the driven member 7 as a friction member by the urging force of the urging member 73, and The drive side member 7 is connected.

When the number of revolutions of the crankshaft 1 exceeds a predetermined number of revolutions, the first piston 65 moves in the direction perpendicular to the axis of the crankshaft 1 due to centrifugal force and enlarges the first liquid chamber 67. As a result, the pressure of the first liquid chamber 67 is reduced to the second liquid chamber 71.
As the liquid becomes lower and the liquid moves from the second liquid chamber 71 to the first liquid chamber 67, the second piston 69 presses and contracts the urging member 73 and separates from the driven side member 7.

Therefore, also in the present embodiment, the coupling and disengagement of the driving member 3 and the driven member 7 can be gradually performed, and the direction of the centrifugal force of the first piston 65 can be changed via the fluid. It can be used effectively.

In this embodiment, the first piston 65
Is set smaller than the pressure receiving area of the second piston 69, a larger axial force is applied to the second piston 69.
Act on. That is, the spring force of the urging member 73 that presses the second piston 69 against the driven-side member 7 can be set large, so that more reliable torque transmission becomes possible and the weight of the first piston 65 as a mass body is reduced. Can be.

In the first to third embodiments, the centrifugal clutch mechanisms 27, 41, and 59 are configured to be supported by the driving member 3, but they are configured to be supported by the driven member 7. It is also possible. According to such a configuration, it is possible to greatly suppress the occurrence of vibration due to imbalance particularly during high rotation of the crankshaft 1. Further, the connection structure of the sub flywheel includes one that is directly fixed to the driven side member irrespective of the above embodiment.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part according to the first embodiment of the present invention.

FIG. 3 is a front view of a main part according to the first embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a part IV in FIG. 3;

FIG. 5 is a sectional view of a main part according to a second embodiment of the present invention.

FIG. 6 is a front view of a main part according to a second embodiment of the present invention.

FIG. 7 is a sectional view according to a third embodiment of the present invention.

FIG. 8 is a sectional view of a main part according to a conventional example.

FIG. 9 is a cross-sectional view of a centrifugal clutch mechanism according to a conventional example.

FIG. 10 is a sectional view of a main part according to another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crankshaft 3 Drive side member 5 Main flywheel 7 Driven side member 9 Radial bearing 23 Sub flywheel 27, 41, 59 Centrifugal clutch mechanism 29, 29a, 29b Elastic plate 31, 31a, 31b, 53 Mass body 35 Depression 37 Convex part 43 Female thread part 45 Male thread member 47 Friction member 49 Biasing member 51 Arm part 57 Engagement concave part 61 First cylinder 63 Second cylinder 65 First piston 67 First liquid chamber 69 Second piston 71 Second liquid chamber 73 Force member

Claims (12)

[Claims] A driving member fixed to a crankshaft; a driven member bearing-supported by the driving member; a sub flywheel connected to the driven member; A centrifugal clutch mechanism that disconnects when a predetermined rotation is exceeded between the driven member and the driven member, wherein the centrifugal clutch mechanism is fixed to one of the driven member or the driven member. An elastic plate that engages with the other and is elastically deformable outwardly in a direction perpendicular to the axis of the crankshaft to be disengaged; and a mass body provided on the elastic plate and elastically deforming the elastic plate by centrifugal force. A torque fluctuation reducing device, comprising: a plurality of sets each including a plurality of sets in a circumferential direction between the driving-side member and the driven-side member, wherein each of the mass bodies selectively has a different weight. 2. The torque fluctuation reducing device according to claim 1, wherein concave portions or convex portions are provided at predetermined circumferential intervals on an outer periphery of the driven member or the driving member, and the relatively heavy mass is provided. The elastic plate in which the body is set is provided with a convex portion or a concave portion which is circumferentially engaged with the concave portion or the convex portion, and the elastic plate in which the relatively light mass body is set is the driven side member or the driving side member. A torque fluctuation reducing device, which is frictionally engaged on an outer periphery of a torque fluctuation reducing device. 3. The torque fluctuation reducing device according to claim 2, wherein a bending rigidity of the elastic plate having the concave portion or the convex portion is smaller than a bending rigidity of the other elastic plates. apparatus. 4. The torque fluctuation reducing device according to claim 2, wherein an engaging portion is provided between the elastic plates so as to engage inward and outward in a direction perpendicular to a crankshaft axis, and from the radially outer side. A torque fluctuation reduction device, wherein a mass body of an elastic plate to be engaged is set heavier than a mass body of an elastic plate to be engaged from the radial inside. 5. The torque fluctuation reduction device according to claim 1, wherein the elastic plate is formed of two layers of metal material in a direction perpendicular to a crankshaft axis, and is formed radially inward. A torque fluctuation reduction device, wherein the expansion coefficient of a layer outside the layer is set to be large. 6. A driving-side member fixed to a crankshaft, a driven-side member bearing-supported by the driving-side member, a sub-flywheel connected to the driven-side member, and the driving-side member A torque fluctuation reduction device including a centrifugal clutch mechanism that disconnects when the rotation exceeds a predetermined rotation between the driven member and the driven member, wherein the centrifugal clutch mechanism is provided on an outer peripheral side of the driving member or the driven member. A female screw portion having a central axis in the crankshaft axial direction, a male screw member screwed into the female screw portion, and a friction member provided at one end of the male screw member and capable of frictionally engaging with the driven side member or the drive side member. A frictional member which is interposed between the male screw member and the driving side member or the driven side member and rotationally urges the male screw member to one side with respect to the female screw portion, thereby causing the friction member to frictionally contact the driven side member or the driving side member. Congruence A biasing member, an arm portion having one end fixed to the other end of the male screw member and extending in a direction perpendicular to the crankshaft axis, and a mass body fixed to the other end of the arm portion. Torque fluctuation reduction device. 7. The torque fluctuation reducing device according to claim 6, wherein the centrifugal clutch mechanism includes the female screw portion, a male screw member,
A set of a friction member, a biasing member, an arm portion, and a mass body, a plurality of which are provided in a circumferential direction between the driving side member and the driven side member, wherein each mass body is selectively different in weight. Characteristic torque fluctuation reduction device. 8. The torque fluctuation reducing device according to claim 7, wherein a diameter of the friction member having a relatively heavy mass between the respective masses is set to be smaller than a diameter of the friction member having the lighter mass. A torque fluctuation reducing device which is set smaller than the diameter of the friction member, and wherein the driven side member or the driving side member is provided with an engagement recess having a diameter between the two diameters of the friction member. . 9. The torque fluctuation reducing device according to claim 7, wherein a protrusion or a recess is provided in a friction member having a mass member that is relatively heavy among the respective mass members, and the driven member or the driving member is provided. A torque fluctuation reducing device comprising a side member provided with a concave portion or a convex portion for engaging the convex portion or the concave portion. 10. A driving-side member fixed to a crankshaft, a driven-side member bearing-supported by the driving-side member, a sub-flywheel connected to the driven-side member, and the driving-side member A torque fluctuation reduction device comprising: a first cylinder having a center axis in a direction perpendicular to a crankshaft axis; A second cylinder having a central axis in a shaft axis direction; a first liquid chamber provided in the first cylinder, the first liquid chamber being moved by a centrifugal force outward in a direction perpendicular to a crankshaft axis;
A first piston that expands a liquid chamber and a second piston that is provided in the second cylinder and that forms a second liquid chamber that communicates with the first liquid chamber and is frictionally engageable with the driven member or the driving member. And a biasing member for biasing the second piston to the driven side member or the driving side member to frictionally engage the second piston. 11. The torque fluctuation reducing device according to claim 10, wherein a pressure receiving area of the first piston is smaller than a pressure receiving area of the second piston. 12. The torque fluctuation reducing device according to claim 1, wherein the centrifugal clutch mechanism is supported by the driven member.