JPH0310432Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a torque fluctuation absorbing flywheel for reducing torque fluctuations transmitted from a vehicle engine to a drive system.

[Prior Art] In order to reduce vibration transmission from the vehicle engine to the passenger compartment, reduce cabin noise, and improve ride comfort, conventional flywheels have been constructed by combining an engine-side flywheel and a clutch-side flywheel. 2
A two-part flywheel has been proposed in which both flywheels are connected via an elastic body.

However, such a two-part flywheel exhibits a good vibration damping function in the normal engine speed range, that is, when the amplitude between the two flywheels is small, but at idle speeds etc. In the low rotational speed range, torsional resonance may occur and the amplitude between the flywheels may increase. Therefore, in order to prevent this resonance phenomenon,
Various proposals have been made in the past to provide a vibration damping mechanism between both flywheels (for example,
-25907, Utility Model No. 55-166926).

As one of the proposals of this kind, the present applicant previously proposed a system consisting of labyrinth-shaped fins fixed to each of the flywheels, and a viscous fluid sealed between the labyrinth-shaped fins, between the two flywheels. A method of providing a viscous damping mechanism has been proposed.

[Problems to be solved by the invention] However, simply providing a viscous damping mechanism as described above may leave the following problems.

In other words, although viscous damping suppresses large amplitude vibrations in the low rotational speed range and prevents resonance, the problem is that in the normal rotational speed range, the vibration damping function of the two-split flywheel is actually reduced. There is.

In order to solve this problem, the applicant first
In a torque fluctuation absorbing flywheel equipped with a viscous damping mechanism consisting of labyrinth-like fins and viscous fluid between them, a torque fluctuation absorbing flywheel that can change the performance of the damping mechanism according to the engine speed has been proposed (and has not been put into practice). (Gan Sho 59-75869),
This prevents resonance phenomena in the low rotation speed range,
In the normal rotation speed range, the two-split flywheel's excellent ability to absorb torque fluctuations can be demonstrated. That is, the above-mentioned Japanese Utility Model Application No. 75869/1987 applies a damping mechanism having a variable damping coefficient dependent on the number of turns to a two-part flywheel.

This invention takes advantage of the fact that the relative torsion angle (width) of the two flywheels increases during resonance,
A damping mechanism with an amplitude-dependent variable damping coefficient is applied to the split type flywheel, thereby increasing the damping coefficient near the resonance frequency to prevent abnormal vibrations due to resonance between the two flywheels, and to prevent abnormal vibrations due to resonance between the two flywheels. When using, reduce the damping coefficient and
The purpose is to reduce rotational fluctuations of the output flywheel. In other words, the present invention achieves the same object as Utility Model Application No. 75869/1983, etc., by means of an amplitude-dependent damping mechanism.

[Means for solving the problem] In order to achieve this objective, in the torque fluctuation absorbing flywheel of the present invention, the flywheel is divided into two parts: an engine side flywheel and a clutch side flywheel. The flywheel is connected via an elastic body. Labyrinth-like fins extending in the flywheel circumferential direction and fixed to each of the flywheels and meshing with each other at intervals are provided between the two flywheels;
A viscous damping mechanism including a viscous fluid sealed between the labyrinth-shaped fins is provided, and the distance between the labyrinth-shaped fins of the damping mechanism is varied in the circumferential direction. That is, the gap between the labyrinth-shaped fins is set to be large when the relative twist angle of the two-part flywheel is small, and small when the relative twist angle is large.

[Function] In such a torque fluctuation absorbing flywheel, during normal torque fluctuations, the relative torsional angle between the engine-side flywheel and the clutch-side flywheel is small, so the distance between the labyrinth-shaped fins is large, and the damping is reduced. The coefficient is small, and the good torque fluctuation absorption effect inherent to a two-split flywheel can be obtained.

However, when the engine reaches a region close to resonance in the low-speed rotation range, the relative torsion angle between both flywheels increases, and the distance between the labyrinth-shaped fins enters a vibration region where it is small. Therefore, large viscous damping acts between the labyrinth-like fins, vibrations with large amplitudes are attenuated, and resonance phenomena are suppressed. This is because the damping coefficient is inversely proportional to the distance between the fins.

[Embodiments] Preferred embodiments of the torque fluctuation absorbing flywheel of the present invention will be described below with reference to the drawings.

1 to 4 show embodiments of the present invention. First, as shown in Figures 1 and 2,
The flywheel consists of engine side flywheel (drive side flywheel) 1 and clutch side flywheel (driven side flywheel) 2.
It has a split configuration, with both flywheels 1 and 2
are arranged on the same axis via a bearing 3 so as to be relatively rotatable. The engine-side flywheel 1 and the clutch-side flywheel 2 are connected via a spring mechanism 4 and a damping mechanism 5, which are provided in parallel with each other.

The engine-side flywheel 1 is fixed to the crankshaft 7 with bolts 6, and is configured to rotate together with the crankshaft 7. A starter ring gear 8 is fixed to the outer periphery of the engine-side flywheel 1 by shrink fitting, press fitting, or the like. The engine-side flywheel 1 is composed of an engine-side flywheel main body 1a and a plate 1b from the perspective of assembly, and both 1a and 1b are integrally connected to each other by bolts 9.

During assembly, the clutch side flywheel 2 is
It consists of a clutch-side flywheel body 2a and a driven plate 2b, and both 2a and 2b are integrally connected by bolts 10.

The spring mechanism 4 is composed of a coil spring extending in the circumferential direction of the flywheel, and includes a radially outward projecting portion 1c of the engine-side flywheel 1 and a radially inward projecting portion 2c of the clutch-side flywheel 2.
It is interposed between the flywheels 1 and 2 to elastically transmit torque between the flywheels 1 and 2.

The damping mechanism 5 includes a plurality of annular labyrinth-shaped fins 11 formed on the side surface of the engine-side flywheel 1 and whose central axis is the center axis of the flywheel, and a plurality of annular labyrinth-shaped fins 11 formed on the side surface of the clutch-side flywheel 2. a plurality of annular labyrinth-like fins 12 whose center axis is the center axis of the wheel;
and oil 13 sealed between them. The labyrinth-like fins 11 and 12 are alternately shifted from each other in the radial direction and are engaged with each other with a gap between them, thereby forming a labyrinth.

The gap between the labyrinth-like fins 11 and the labyrinth-like fins 12 is changed depending on the relative torsional angle between the engine-side flywheel 1 and the clutch-side flywheel 2. That is, when the relative torsional angle between the engine-side flywheel 1 and the clutch-side flywheel 2 is zero (the state shown in FIG. 2) or small (the state shown in FIG. 3), both labyrinth-like fins 1
When the radial distance t ₁ between 1 and 12 is large and the relative torsional angle between the engine side flywheel 1 and the clutch side flywheel 2 is large (the state shown in Fig. 4)
In this case, the radial distance t ₂ between both labyrinth-like fins 11 and 12 is set small. oil 13
is sealed in the labyrinth portion by oil seals 14 and 15. The damping mechanism 5 having the above structure has _a damping characteristic as shown in _{FIG .} bigger
Changes to C ₂ .

FIG. 6 shows an embodiment of the invention having a different configuration from FIGS. 1 to 4, in which:
The distance between the labyrinth-like fins 16 and 17 is gradually changed as the relative torsion angle of both flywheels 1 and 2 changes. The damping mechanism 5 having such a configuration has a relative torsion angle θ-damping coefficient C characteristic as shown in FIG. 7, and the damping coefficient C increases with the relative torsion angle of both flywheels 1 and 2.

Next, the operation of the two-part flywheel of the present invention will be explained.

The fluctuating torque of the engine is transmitted from the crankshaft 7 to the engine-side flywheel 1, and is located at the clutch-side flywheel 2 via the spring mechanism 4 and damping mechanism 5.
Torque fluctuations are absorbed by the vibration system constituted by the mass of both flywheels 1 and 2, the spring of spring mechanism 4, and the damping of damping mechanism 5.

Since the damping mechanism 5 has an amplitude-dependent variable damping coefficient, the following characteristics can be obtained depending on the operating state. That is, in normal usage conditions outside of the resonance region, the relative torsion angle (width) of the two flywheels, the engine-side flywheel 1 and the clutch-side flywheel 2, is small, so the labyrinth-like fins 11, 12, or 16 ,17 is
As shown in FIG. 2, FIG. 3, or FIG. 6, a large spacing t ₁ is maintained, and the damping coefficient of oil, which is inversely proportional to the distance between the fins, is small. Therefore,
Since it receives little resistance from the damping mechanism 5, the two-split flywheel has a large torque fluctuation absorption effect.

On the other hand, when the engine speed falls into the low speed range and approaches the resonance range, the relative torsion angle between the engine side flywheel 1 and the clutch side flywheel 2 increases, and the labyrinth-like fins 11, 12 or 16, 17 The interval becomes a small interval _t2 shown in FIG. 4 or 6 at that frequency, and at this time the damping coefficient of the damping mechanism 5 becomes large. Therefore, resonance of the two-part flywheel is suppressed.

[Effects of the invention] As explained above, when using the torque fluctuation absorbing flywheel of the present invention, the two-split flywheel is connected by a spring and a damping mechanism with an amplitude-dependent variable damping coefficient, so that the resonant frequency region is reduced. During normal operation, the distance between the labyrinth fins is increased to increase the damping coefficient, thereby suppressing resonance, and during normal operation, the distance between the labyrinth fins is increased to decrease the damping coefficient, thereby reducing torque. Fluctuations can be absorbed effectively.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a torque fluctuation absorbing flywheel according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the damping mechanism of the flywheel shown in FIG. 1 in a direction perpendicular to FIG. 1, and FIG. is an enlarged sectional view of the damping mechanism section of the flywheel shown in FIG. 2 at a small swing width, FIG. 4 is an enlarged sectional view of the damping mechanism section of the flywheel shown in FIG. 2 at a large swing width, and FIG. The relative torsion angle-damping coefficient characteristics diagram of the flywheel shown in FIGS. 1 to 4, and FIG. 6 shows the damping mechanism section of the torque fluctuation absorbing flywheel according to an embodiment different from those shown in FIGS. 1 to 4 of the present invention. The enlarged sectional view, FIG. 7, is a relative torsion angle-damping coefficient characteristic diagram of the flywheel shown in FIG. 6. 1... Engine side flywheel, 2... Clutch side flywheel, 4... Spring mechanism, 5...
Damping mechanism, 11, 12, 16, 17...labyrinth-like fins, 13...oil.

Claims (1)

[Scope of utility model registration request] The flywheel is divided into two parts, the engine side flywheel and the clutch side flywheel.
In a torque fluctuation absorbing flywheel in which both flywheels are connected via an elastic body, a labyrinth-like structure is provided between both flywheels that extends in the flywheel circumferential direction, is fixed to each of both flywheels, and meshes with each other at intervals. A torque fluctuation absorbing flywheel characterized in that a damping mechanism comprising fins and a viscous fluid sealed between the labyrinth-shaped fins is provided, and the distance between the labyrinth-shaped fins of the damping mechanism is varied in the circumferential direction.