JPH0648032B2 - Flywheel assembly - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flywheel assembly that absorbs torsional vibration of a drive train of an automobile, for example.

(Prior Art and its Problems) In FIG. 3, which models the structure of a conventional clutch disc, 10 is an input side from an engine, and 12 is an output side for transmitting power to a transmission or the like. A first stage torsion spring 14a, a second stage torsion spring 14b, and a third stage torsion spring 14c are interposed between the input side 10 and the output side 12, and the second stage torsion spring 14b and the third stage torsion spring 14c are provided. Are provided with gaps 14d and 14e having a predetermined twist angle. Further, the first-stage hysteresis torque generating mechanism 16a and the second-stage hysteresis torque generating mechanisms 16b and 16c are also interposed, and the second-stage hysteresis torque generating mechanism 16b and the third-stage hysteresis torque generating mechanism 16c have a gap 16d,
6e is provided.

In the above-mentioned conventional example, as shown in FIG. 4, as the torsion angle increases, the torsion characteristic shows the first-stage torsion spring 14
a and the first-stage hysteresis characteristic Kd1 and the first-stage hysteresis characteristic Th generated by the first-stage hysteresis torque generating mechanism 16a.
Although it changes from 1 to the third stage torsional characteristic Kd3 and the third stage hysteresis characteristic Th3 generated by the third stage torsion spring 14c and the third stage hysteresis torque generating mechanism 16c, this characteristic has the following problems.

That is, the first-stage torsion characteristic Kd1 to the third-stage torsion characteristic Kd3 are set small as a countermeasure against abnormal noises such as the rattling noise generated by the transmission during neutral and the rattling noise generated by the transmission and the differential mechanism during traveling. However, it is preferable to set the first-stage torsion characteristic Kd1 to the third-stage torsion characteristic Kd3 to a large value as a countermeasure against low-frequency vibration.

Therefore, the torsional characteristics shown in FIG. 4 must be set according to the characteristics required for each vehicle, and more recently, the required level of noise and vibration prevention for the clutch has become higher and higher, and characteristics that conventional structures cannot meet. That is, as described above, there is a case where the countermeasures against the abnormal noise and the countermeasure against the low frequency vibration are simultaneously demanded.

Therefore, a technology has been developed in which the vibration from the engine is positively absorbed even in the flywheel.

For example, as shown in FIG. 5, a conventional clutch disc 2
0, between the flywheel 22 and the crankshaft 24, the auxiliary flywheel 26a and the damper portion 26b are connected in series, or as shown in FIG. 6, the auxiliary flywheel is arranged in parallel with the flywheel 22 via a torsion spring 26c. There is a prior art in which 26a is provided.

As shown in FIG. 7, the applicant of the present invention also has a first flywheel 104 fixed to the crankshaft 100 of the engine and having a clutch disc 102 intermittently connected to the flywheel assembly of this type, and is concentric with the first flywheel. Second flywheel 106 provided and set to a predetermined mass
A damper mechanism 108 for elastically connecting both flywheels, and an output from the second flywheel 106 to the spline hub 110 of the clutch disc 102 only when the clutch disc 102 is in contact with the first flywheel 104. Friction damping mechanism 1 for transmitting and damping vibration
12 has been developed and has already been filed (Japanese Patent Application No. 60-44298, filing date:
(6th March, 1985).

On the other hand, in order to damp torsional vibration of a so-called drive transmission system from an engine output shaft of an automobile to a drive wheel, for example, an inertia shear damper set to a predetermined mass may be provided on a propeller shaft. When there are a plurality of peaks having different vibration frequencies, the damping characteristics corresponding to the frequency of each peak cannot be exhibited.

Therefore, the present inventor devises the present invention, instead of the inertia shear damper, with the intention of attenuating the vibration of the drive transmission system having a plurality of peaks with different vibration frequencies in the flywheel assembly in place of the inertia shear damper. Came to.

(Object of the Invention) The present invention provides a flywheel assembly that can utilize a part of the mass of a flywheel to damp torsional vibration of a drive transmission system having a plurality of peaks having different vibration frequencies. The purpose is to do.

(Structure of the Invention) (1) Technical Means The present invention relates to a first flywheel fixed to a crankshaft of an engine and having an intermittent clutch disc, and a first flywheel concentrically supported by the first flywheel and set to a predetermined mass. The two flywheels and the friction damping mechanism that couples the inertial mass of the second flywheel to the spline hub of the clutch disc only when the clutch disc is in contact with the first flywheel to damp the torsional vibration of the drive transmission system. In the flywheel assembly provided, the outer peripheral portion of the first flywheel and the crankshaft are connected by a relatively thin connecting plate arranged along the end surface of the second flywheel opposite to the clutch disc, and the second flywheel is connected. The damper inertia portion of the wheel is supported so as to be swingable in the circumferential direction with respect to the inner peripheral flange portion of the second flywheel. And a ring-shaped friction plate axially slidably provided on the spline hub of the clutch disc. The flywheel assembly is characterized in that a spring member that is fixed and that urges the friction plate and the friction member toward the second flywheel is interposed between the friction plate and the spline hub.

(2) Action The damper inertia portion of the second flywheel is connected to the drive transmission system by the friction damping mechanism via the multistage damper mechanism only when the clutch disc is pressed against the first flywheel. Damps torsional vibrations of the system.

The multi-stage damper mechanism damps torsional vibration of a drive transmission system having a plurality of peaks with different vibration frequencies.

(Embodiment) A clutch to which the present invention is applied will be described with reference to FIG.

In FIG. 1, 30 is an engine crankshaft. A first flywheel 32 is fixed to the rear end of the crankshaft 30 with a relatively thin connecting plate 31 described later in detail. The facing surface 35a of the clutch disc 34 contacts the annular surface 33a of the first flywheel 32. A ring gear 33b is formed on the outer peripheral portion of the first flywheel 32 in the radial direction, and the power of a known starter motor (not shown) is input from the ring gear 33b. Further, the connecting plate 31 and the first flywheel 32 are fixed by, for example, rivets 31b provided at eight locations at equal intervals in the circumferential direction.

The clutch cover 3 is provided on the rear end surface of the first flywheel 32.
5b is fixed, and the clutch cover 35b holds a pressure plate 35e via a wire ring 35c and a diaphragm spring 35d.

The first flywheel 32 has a substantially disc shape, and
A second flywheel 36 is provided on the front of the flywheel 32.
However, as will be described later in detail, it is provided concentrically with the first flywheel 32 and in a rotatable state.

The second flywheel 36 has a flange portion 37a on the inner peripheral portion,
For example, the damper inertia shear portion 3 divided into two on the outer peripheral portion
7b and 37b 'have a substantially annular shape, and damper inertia shear portions 37b and 37b' are respectively connected to the rear stage of the clutch. The inertia mass of a drive transmission system such as a transmission (not shown) and the vibration characteristics described later in detail. Is set to a predetermined mass corresponding to.

The outer peripheral portion of the damper inertia portion 37b on the outer peripheral side and the first
An outer peripheral support mechanism 70 is interposed between the inner peripheral portion of the ring gear 33b fixed to the flywheel 32.
The outer peripheral support mechanism 70 is composed of a steel ball 72, a nut 74, and the like. An annular groove 76 having a substantially regular triangular cross section is formed on the entire inner circumference of the ring gear 33b. A tapered surface 78 is formed around the entire circumference of the damper inertia portion 37b so as to face the annular groove 76, and a large number of steel balls 72 are provided between the tapered surface 78 and the annular groove 76. , Are rotatably housed in pressure contact with the tapered surface 78. Further, a screw portion 80 is formed on the front end portion of the outer peripheral portion of the damper inertia shear portion 37b, and the nut 74 having a substantially annular shape is screwed into the screw portion 80. The nut 74 is also formed with a tapered surface 82 that faces the annular groove 76, and the tapered surface 82 is pressed against the steel ball 72 to hold the steel ball 72.

Torsion springs 38, 38 '(multi-stage torsion damper mechanism) are respectively contracted between the damper inertia shear portions 37b, 37b' and on the inner peripheral portion of the damper inertia shear portion 37b as described later in detail. The inertial portion 37b and the clutch disc 34 are elastically connected via a friction damping mechanism 40.

For example, the torsion spring 38 'on the inner peripheral side is a recess 84 formed on the inner peripheral portion of the damper inertia portion 37b'.
The recesses 84 are formed in, for example, six places at equal intervals in the circumferential direction of the damper inertia shear portion 37b '. A spring retainer 86 that is integral with the damper inertia portion 37b 'and two spring retainers 90 that are integral with the damper hub 88 that fits into the ball bearing 37c extend into the recess 84, and the spring retainer 8
A torsion spring 38 'is contracted between 6 and the spring retainer 90. The damper hub 88 has a substantially annular shape that is continuous over the entire circumference.
It has become. In addition, the torsion spring 3 on the outer peripheral side
8 is also reduced.

A ball bearing 37c is interposed between the flange portion 37a and the damper inertia shear portion 37b, and the damper inertia shear portion 37b is rotatably supported by the flange portion 37a by the ball bearing 37c. The flange portion 37a is a bolt 31a, and the connecting plate 31 is arranged along the front end surface of the second flywheel 36.
It is fixed to the crankshaft 30 while being fastened together with the inner peripheral portion of the. Reference numeral 37d in the figure is a bearing retainer.

As shown in FIG. 1, the friction damping mechanism 40 is interposed between the damper inertia portion 37b and the spline hub 35f of the clutch disc 34. In this friction damping mechanism 40, the facing 35a is the first fly. The torsional vibration generated in the above-mentioned drive transmission system is attenuated when the clutch, which is in pressure contact with the pressure contact surface 33a of the wheel 32, is engaged.

The friction damping mechanism 40 includes a cone spring 46 (spring member), a facing 48 (friction member), and a friction plate 5.
It is composed of 0 etc. The friction plate 50 is made of a substantially annular thin plate, and the inner peripheral portion of the friction plate 50 is fixed to the hub 42. The spline inner teeth 42a of the hub 42 mesh with the spline outer teeth 42b of the spline hub 35f in a slidable state in the axial direction. A cone spring 46 is interposed between the hub 42 and the spline hub 35f, and the friction plate 50 and the facing 48 are pressed forward by the spring force of the cone spring 46.

A facing 48 is adhered to the front surface of the outer peripheral portion of the friction plate 50, and the facing 48 is in sliding contact with the pressure contact surface 44 of the damper hub 88 of the damper inertia portion 37a. The pressure contact surface 44 is formed in an annular shape that is continuous in the circumferential direction of the second flywheel 36.

As shown in FIG. 2 which models the above clutch structure, the clutch disk 34 and the damper inertia parts 37b and 37b 'of the second flywheel 36 (inertia mass:
I _D , I _D ′) is the first flywheel 32 (inertial mass:
I _F ) and are arranged in parallel. The damper inertia portions 37b and 37b 'are provided with a bearing 37c and an outer peripheral support mechanism 70 (first
In the figure), it is axially supported separately from the first flywheel 32.

Further, the clutch disc 34 is provided with a torsion spring 35g and a hysteresis torque generating mechanism 35h in parallel with each other. Facings 48 for generating hysteresis torque are provided in series on the second flywheel 36. A drive transmission system including a transmission T, a propeller shaft 130, a differential mechanism 134, an axle 136, a tire 138 and the like is connected to a stage subsequent to the clutch disc 34.

Next, the operation will be described. The facing 35a is attached to the annular surface 3 of the first flywheel 32 by the pressure plate 35e.
When the clutch is pressed against 3a, the clutch disc 34 is pressed by the spring force of the diaphragm spring 35d.
Slides on the spline shaft of the transmission (not shown) toward the first flywheel 32, and the friction plate 50 comes into pressure contact with the facing 48. At this time, the cone spring 46 is deformed by its own elasticity due to the pressure contact force from the friction plate 50, and the friction plate 50 and the facing 48 are always in pressure contact with each other with a constant pressing force, so that the friction generated between the facing 48 and the friction plate 50. Power is also constantly maintained.

In the above clutch connection state, the first flywheel 32
The engine power input to the clutch disc 34
And the inertia masses I _D and I _D ′ of the damper inertia shear portions 37b and 37b ′ of the second flywheel 36 are transmitted to the transmission through the torsion spring 3 and
It is connected to the drive transmission system of the transmission T or the like via 8, 38 ', the facing 48, and the friction plate 50.

Therefore, as shown in FIG. 2a showing the change in the magnitude G of the vibration with respect to the rotation speed f, even when the peaks P1 and P2 of different rotation speeds are generated in the torsional vibration characteristic X generated in the drive transmission system, The resonance points Q1 and Q2 generated by the spring force (the spring coefficient is appropriately adjusted) of the damper inertial portions 37b and 37b 'and the torsion springs 38 and 38' of the second flywheel are set to the peak P1 of the characteristic X,
By synchronizing with P2, the vibration characteristic Y of the drive transmission system, which is a combination of the characteristic X and the damper characteristic, is attenuated to such an extent that the magnitude G is of practically no problem, and the transmission T ( It is not necessary to provide the inertia shear damper 132 on the propeller shaft 130 or the like in the latter stage of FIG. 2). Therefore, it is not necessary to provide an extra mass of the damper 132 in the drive transmission system from the transmission T to the tire 138, and the inertial mass of the entire drive transmission system is reduced.

Further, since the damper inertiar portions 37b and 37b 'are arranged in front of the transmission T, the torsional vibration damping effect of the damper inertiar portion 37b is not affected by the reduction ratio of the transmission T and is always constant. Stable work in the state.

Since the connecting plate 31 is relatively thin, the bending vibration of the first flywheel 32 about the axis perpendicular to the axis O, which occurs when the clutch disc 34 is intermittently connected to the first flywheel 32, is connected. The elasticity of the plate 31 absorbs.

When the engine is started, the power from the starter motor (not shown) is input to the ring gear 33b of the first flywheel 32. This power is supplied to the ring gear 33b.
Is transmitted directly to the crankshaft 30 through the connecting plate 31.

Further, when the facings 35a and 48 are worn for a long period of time, the friction plate 50 together with the clutch disc 34 should be used when replacing the entire clutch disc 34.
The facing 48 is also replaced together. Therefore, all consumable parts of the friction damping mechanism 40 are provided on the clutch disc 34 side, and there is no need to disassemble the first flywheel 32 and the second flywheel 36 side.

(Effects of the Invention) As described above, the flywheel assembly of the present invention is
A first flywheel 32 fixed to the crankshaft 30 of the engine and having a clutch disc 34 connected and disconnected, a second flywheel 36 supported concentrically with the first flywheel 32 and set to a predetermined mass, and a second flywheel 36. The inertia mass _ID of the damper inertia shear portion 37b of the spline hub 35f of the clutch disc 34 is set only when the clutch disc 34 is in contact with the first flywheel 32.
In a flywheel assembly including a friction damping mechanism 40 that is connected to the first flywheel 32 to damp torsional vibrations of the drive transmission system.
Are connected by a relatively thin connecting plate 31 arranged along the end surface of the second flywheel 36 on the side opposite to the clutch disc, and the damper inertia shear portion 37b of the second flywheel 36 is connected to the first flywheel 32. An outer peripheral support mechanism 70 that swingably supports in the circumferential direction is provided, and, for example, two divided damper inertia shear portions 37b and 37 'are provided, and the respective damper inertia shear portions 37b and 37 are provided.
Torsion springs 38, 38 '(multi-stage torsion damper mechanism) for connecting b'to the friction damping mechanism 40 are provided,
The torsion spring 38 is provided with a bearing 37c that rotatably supports the crankshaft 30 with respect to the crankshaft 30, and a damper hub 88 is formed with a pressure contact surface 44 against which the facing 48 of the friction damping mechanism 40 is pressed. 34 is fixed to a substantially annular friction plate 50 provided slidably in the axial direction on the spline hub 35f, and the friction plate 50 and the facing 48 are disposed between the friction plate 50 and the spline hub 35f in the second flywheel direction. Since the biasing cone spring 46 (spring member) is interposed, the following effects can be obtained.

As shown in FIG. 2a showing the change in the magnitude G of the vibration with respect to the rotation speed f, even if the rotational vibration peaks P1 and P2 which are different in the torsional vibration characteristic X generated in the drive transmission system described above are generated, Flywheel damper inertia part 3
7b, 37b 'and torsion springs 38, 38'
The resonance points Q1 and Q2 generated by the spring force (the spring coefficient is appropriately adjusted) can be synchronized with the peaks P1 and P2 of the characteristic X.

Therefore, the vibration characteristic Y of the drive transmission system, which is a combination of the characteristic X and the damper characteristic, is attenuated to such an extent that the magnitude G is practically negligible, and, for example, the propeller at the rear stage of the transmission T is conventionally used. It is not necessary to provide the inertia shear damper 132 on the shaft 130 or the like. Therefore, it is not necessary to provide an extra mass of the damper 132 in the drive transmission system, and the inertial mass of the entire drive transmission system can be reduced.

Further, since the damper inertia parts 37b and 37b 'are arranged in the front stage of the transmission T, the torsional vibration damping effect of the damper inertia part 37b is not affected by the reduction ratio of the transmission T and is always in a constant state. Thus, the stable torsional vibration damping effect can be exhibited.

Since the connecting plate 31 is relatively thin, the bending vibration of the first flywheel 32 about the axis perpendicular to the axis O, which occurs when the clutch disc 34 is intermittently connected to the first flywheel 32, is connected. It can be absorbed by the elasticity of the plate 31.

In the present specification, friction includes all friction phenomena such as dry friction and viscous friction.

(Other Embodiments) (1) The damper inertia shear portions 37b and 37b 'are not limited to being divided into two as in the embodiment, but may be divided into multiple stages such as three divisions and four divisions.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view of a clutch to which the present invention is applied, FIG. 2 is a structural schematic diagram modeling the structure of FIG. 1, and FIG. 2a is a graph showing the change in the magnitude of vibration with respect to the rotational speed. FIG. 3 is a structural schematic diagram showing a conventional example, FIG. 4 is a graph showing the torsional characteristics of the conventional example of FIG. 3, FIGS. 5 and 6 are structural schematic diagrams showing other prior examples, and FIG. It is a longitudinal cross-sectional view showing a prior art example. 30 ... Crankshaft, 31 ... Connection plate, 32 ... First flywheel, 34 ... Clutch disc, 36 ... Second flywheel, 37b ... Damper inertia section, 38, 38 '... Torsion spring , 40 ... Friction damping mechanism, 42 ... Hub, 46 ...
… Cone spring, 48 …… Facing, 50 ……
Friction plate, 70 ... Outer peripheral support mechanism

Claims (1)

[Claims] 1. A first flywheel fixed to a crankshaft of an engine and having a clutch disc connected and disconnected, and a second flywheel supported concentrically with the first flywheel and having a predetermined mass.
A flywheel; and a friction damping mechanism for connecting the inertial mass of the second flywheel to the spline hub of the clutch disc only when the clutch disc is in contact with the first flywheel to damp torsional vibration of the drive transmission system. In the flywheel assembly described above, the outer peripheral portion of the first flywheel and the crankshaft are connected by a relatively thin connecting plate arranged along the end surface of the second flywheel opposite to the clutch disc, An outer peripheral support mechanism is provided to support the damper inertial portion of the first flywheel so as to be swingable in the circumferential direction. The inertial mass of the damper inertiar portion is divided into a plurality of stages, and each divided mass is elastically divided. A multi-stage torsion damper mechanism that is mechanically connected to the friction damping mechanism is provided, and friction damping is partly provided in this multi-stage torsion damper mechanism. The friction member of the structure forms a pressure contact surface for pressure contact, and the friction member is fixed to a substantially annular friction plate axially slidably provided on the spline hub of the clutch disc, and between the friction plate and the spline hub. A flywheel assembly comprising a friction plate and a spring member for urging the friction member toward the second flywheel.