JPH0210843Y2 - - 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 (rotation fluctuations) transmitted from a vehicle engine to a drive system.

[Conventional technology]

Conventionally, a two-piece flywheel has been proposed in order to reduce vibration transmission from a vehicle engine to a passenger compartment, reduce cabin noise, and improve ride comfort. The conventional two-part flywheel is shown in Japanese Patent Application Laid-Open No. 55-25907, and the
As shown in the figure and FIG. 2, the flywheel is divided into two parts: an engine-side flywheel 1 connected to the crankshaft and a clutch-side flywheel 2 connected to the clutch side. 2 connected via a torsion spring 3 extending in the circumferential direction. The torsion spring 3 is housed in a space cut out in both the engine-side flywheel 1 and the clutch-side flywheel 2, and is compressed by the relative angular displacement of both flywheels. That is, the torsional rigidity between both flywheels is determined by the torsion spring 3.

[The problem that the idea aims to solve]

However, since the conventional device has almost no damping function, it produces a sharp resonance peak in the rotation range near the natural frequency determined by both flywheels and the torsion spring 3, as shown by curve A in Figure 9. When vibrated at this natural frequency, it causes intense vibration due to resonance, which causes abnormal noise and discomfort, and has a negative impact on the engine. On the other hand, the advantage of not having damping is that when it is excited at a frequency sufficiently larger than the natural frequency (usually √2 times the natural frequency or more), when it has damping (curve B in Figure 9), In comparison, it can be mentioned that a large vibration reduction effect can be obtained. That is, 2
In a split type flywheel, if you want to obtain the original effect and avoid problems caused by resonance, it is necessary to have large attenuation near the resonance point and attenuation above the resonance point (for example, √2 times the resonance frequency or more). It is effective to make it smaller. Furthermore, it would be more effective if the damping could be changed as necessary for the purpose of improving driving feeling.

In order to alleviate the above-mentioned problems, the present invention increases the damping of vibrations during resonance in a two-part flywheel, reduces the damping in areas outside of the resonance point, and also suppresses changes in this damping. The purpose is to allow arbitrary external control.

[Means to solve the problem]

The above object is achieved according to the present invention by the following torque fluctuation absorbing flywheel. That is, in a torque fluctuation absorbing flywheel in which the flywheel is divided into two, an engine-side flywheel connected to the engine crankshaft and a clutch-side flywheel in contact with the clutch, and both flywheels are connected via a torsion spring, in the torsional direction between both flywheels,
A damping mechanism formed separately from the torsion spring is interposed, and the damping mechanism is mounted on an orifice plate having an orifice supported on one flywheel side of both flywheels, and on both sides in the circumferential direction from the orifice plate. a bellows extending from the flywheel side and engaged with the other flywheel side, the interior of which is filled with a liquid so as to be able to pass through the orifice plate, and further provided with a mechanism for making the diameter of the orifice variable; A torque fluctuation absorbing flywheel characterized by being composed of a limit tube that is movable and has a flange that can be brought into close contact with an orifice plate and can be separated from the orifice plate, and oil that is wound around the orifice axis and assembled to the orifice plate.

[Effect]

In such a torque fluctuation absorbing flywheel, when the engine side flywheel and the clutch side flywheel are relatively displaced in the rotational direction, the orifice plate is supported on one flywheel side, and the bellows is supported on the other flywheel side. Since it is pushed from the side, the fluid in the bellows flows through the orifice in the orifice plate, and viscous damping acts to suppress the amplitude of the vibration of the relative rotation of both flywheels. Therefore, in the torque fluctuation absorbing flywheel of the present invention, resonance is suppressed by the damping action of the damping mechanism, and noise, discomfort, adverse effects on the engine, etc. due to resonance are reduced.

In addition, near idle rotation, a magnetic field is generated in the direction of the orifice axis by passing an electric current through the coil from the outside, and the flange of the limit tube is brought into close contact with the orifice plate to reduce the orifice diameter.
Increase damping. This prevents large amplitudes from occurring even if the resonance point is pulled. In the normal rotation range, which is greater than idle rotation, the coil current is cut off, allowing the limiter tube to vibrate freely, increasing the orifice diameter and reducing damping. This provides a good torque fluctuation absorption effect.

〔Example〕

Hereinafter, preferred embodiments of the torque fluctuation absorbing flywheel of the present invention will be described with reference to the drawings.

3 and 4 show an embodiment of the invention. In the figure, the flywheel is divided into an engine side flywheel 12 that is connected to the engine crankshaft and a clutch side flywheel 1 that is in contact with the clutch side.
4 are connected via a coiled torsion spring 15 extending in the torsional direction (circumferential direction).
The torsion spring 15 is attached to the drive side plate 2 supported by the engine side flywheel 12.
The window 11 formed in It expands and contracts when angular displacement occurs to alleviate torque fluctuations.

A damping mechanism 16 formed separately from the torsion spring 15 is provided in the circumferential direction between the engine-side flywheel 12 and the clutch-side flywheel 14, as shown in FIGS. 5 to 8. . The damping mechanism 16 includes an orifice plate 18 having an orifice 17 and a pair of bellows 19 disposed on both sides of the orifice plate 18 and attached to the orifice plate 18 in a fluid-tight manner. The orifice plate 18 has a protrusion 18
a is engaged with the notches 21 of the pair of drive side plates 20 supported by the engine side flywheel 12, so that it is supported on the engine side flywheel 14 side and rotates together with the engine side flywheel 12. On the other hand, bellows 19
is liquid-tightly fixed to the orifice plate 18 with the end on the orifice plate 18 side open to the orifice plate 18, and has an end plate 22 at the end opposite to the orifice plate 18. The end plate 22 is pushed by the clutch flywheel 14 by being engaged with a notch 24 formed in the driven plate 23 supported by the clutch flywheel 14. Orifice 1 of orifice plate 18
7 is located on the inner diameter side of the bellows 19, and when the bellows 19 on both sides of the orifice plate 18 expand or contract, the liquid 25 filled in the bellows 19 flows through the orifice 17.

A mechanism is provided for the orifice 17 to make the orifice diameter variable. The mechanism consists of a limiter tube 26 and a coil 27. limit tachi tube 2
6 is a tube 26c with a smaller diameter than the orifice diameter.
A flange 26a made of a conductive material is attached to one end of the tube 26c and has a diameter larger than the orifice diameter, and a rubber flange 26b is fixed to the other end of the tube 26c and has a diameter larger than the orifice diameter. The limiter tube 26 has a tube 26c inserted through the orifice 17, and is movable in the axial direction of the orifice. The coil 27 is assembled to the orifice plate 18 and wound around the orifice axis. The coil 27 is controlled to be energized on and off from the outside, and when energized, it generates a magnetic field in the axial direction of the orifice, and the flange 2 of the limiter tube 26
6a and adjust the orifice cross section to tube 26.
Only the inner circumference side passage 28 of c is used, and the orifice diameter is made small. When the coil 27 is de-energized, the limiter tube 26 freely moves in the axial direction, the flange 26a separates from the orifice plate 18, and the cross-sectional area of the orifice changes to the inner circumferential passage 28 of the tube 26c.
and the outer peripheral side 29 of the tube 26c, and the orifice diameter is increased. Electric power for changing the orifice diameter is supplied to, for example, a slip ring 3 attached to the end face of the flywheel with an insulator 30 in between.
1 and 32. That is, the slip rings 31 and 32 and the orifice diameter control coil 27 built into the externally controlled viscous damping mechanism assembly are connected by lead wires.

In the illustrated example, the orifice plate 18 is supported on the engine flywheel 12 side, and the bellows 1
9 is shown in which both ends are engaged with the clutch-side flywheel 14, but when an angular displacement occurs between the engine-side flywheel 12 and the clutch-side flywheel 14, the orifice plate 18 and the bellows 19 Other structures may be used as long as a relative change in position occurs between the two. For example, although not shown, the orifice plate may be pushed toward the clutch-side flywheel, and the bellows may be pushed from the engine-side flywheel-side member.

Next, the operation of the torque fluctuation absorbing flywheel configured as described above will be explained.

The rotation of the engine crankshaft is transmitted from the engine side flywheel 12 to the clutch side flywheel 14 via the torsion spring 15 and damping mechanism 16, and from the clutch to the power train. In this system,
A vibration system is constituted by a mass determined by the flywheels 12 and 14, a spring constant determined by the torsion spring 15, and a damping constant determined by the damping mechanism 16. has a natural frequency determined by the flywheels 12 and 14 and the torsion spring 15, and the damping mechanism 1
It has a damping coefficient determined by 6.

When there is a fluctuation in the torque of the crankshaft, the engine-side flywheel 12 and the clutch-side flywheel 14 vibrate relative to each other to absorb the torque fluctuation. The torque fluctuation transmitted from the engine to the power train is caused by the primary component of engine explosion.
The vibration of the superimposed waveform of the n-th order harmonics is dominant, but once this vibration matches the natural frequency of the flywheel vibration system near the engine idling rotation, it resonates and both flywheels 12 , 14 tend to vibrate with large relative angular displacements.

FIG. 7 shows the relative positional relationship between the orifice plate 18 and the bellows 19 when the drive side plate 20 on the engine side flywheel 12 side and the driven side plate 23 on the clutch side flywheel 14 side are in a neutral state. The figure shows the relative positional relationship between the orifice plate 18 and the bellows 19 when the drive side plate 20 and the driven side plate 23 are relatively angularly displaced from the neutral state shown in FIG. When both flywheels 12 and 14 undergo a relative angular displacement, the orifice plate 18 moves while deforming the bellows 19. On this occasion,
Since the liquid 25 filled in the bellows 19 passes through the orifice 17, viscous damping is obtained due to its viscous resistance. Therefore, even if both flywheels 12 and 14 attempt to generate vibration accompanied by a large angular displacement during resonance, the resonance phenomenon is suppressed to a small level by the damping mechanism 16.

At this time, when the engine is idling, coil 2
7 is energized, the limit tube 26 is pulled to one side and the flange 26a is attracted to the orifice plate 19, resulting in the state shown in FIG. big. Therefore, near idling, as shown by curve B in Fig. 9, the flywheel exhibits greater damping than the conventional flywheel shown in Figs. is controlled. On the other hand, a larger frequency range (√ of natural frequency) than during engine andring
When the coil 27 is de-energized (more than twice), the limiter tube 26 is in a free state in the liquid 25 filled in the bellows 19, that is, the state shown in FIG. 2
Since it flows through both 8 and 29, the viscous damping becomes small. Therefore, in the frequency range higher than the idle speed, as shown by curve C in Figure 9, it has a greater torque fluctuation absorption effect than the vibration characteristic B of a flywheel with a damping element, and vibrations are suppressed. . In this manner, the damping coefficient in the torsional direction between the engine-side flywheel 12 and the clutch-side flywheel 14 changes depending on whether the coil 27 is energized or not. These two states can be arbitrarily selected depending on whether the coil 27 is energized or not, so they can be freely controlled from the outside.In addition to avoiding resonance problems and improving original performance, it is also possible to select characteristics that take into account driving feeling. is also possible.

[Effect of idea]

According to the torque fluctuation absorbing flywheel of the present invention, the following effects can be obtained. In other words, a damping mechanism having an orifice and a bellows is provided on the two-part flywheel, and an orifice diameter variable mechanism consisting of a limiter tube and a coil is provided in the damping mechanism, so the orifice diameter is made small near idling, and the orifice diameter is made small near idling. By increasing the orifice diameter, even if the idling rotation is pulled into the flywheel resonance point, the resonance amplitude can be reduced, and the effect of absorbing torque fluctuations in the normally used rotation range can be kept large. In addition, variable control of the orifice diameter can be controlled from outside the flywheel by simply turning on and off the energization to the coil.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of a conventional two-piece flywheel, Fig. 2 is a cross-sectional view of the flywheel in Fig. 1 taken along the - line, and Fig. 3 is a torque fluctuation according to an embodiment of the present invention. A partially cutaway front view of the absorption flywheel, FIG. 4 is a sectional view taken along the - line in FIG. 3, FIG. 5 is a sectional view taken along the - line in FIG. 3, and FIG. 6 is a sectional view taken along the - line in FIG. 7 and 8 are cross-sectional views of the damping mechanism part of the flywheel shown in the neutral state, respectively. FIG. 9 is a cross-sectional view when the driven side plate is displaced from the neutral state, and FIG. 9 is a characteristic diagram of rotation speed vs. amplitude. 12...Engine side flywheel, 14...
Clutch side flywheel, 15... Torsion spring, 16... Damping mechanism, 17... Orifice, 18... Orifice plate, 19... Bellows, 20... Drive side plate, 23...
Driven side plate, 25...Liquid, 26...Limit tube, 26a...Flange, 27...
coil.

Claims (1)

[Scope of utility model registration request] The flywheel is divided into two parts: an engine-side flywheel connected to the engine crankshaft and a clutch-side flywheel in contact with the clutch. in the torsional direction between the wheels,
A damping mechanism formed separately from the torsion spring is interposed, and the damping mechanism is supported on one flywheel side of both flywheels, and an orifice plate having an orifice, and extending from the orifice plate to both sides in the circumferential direction. and a bellows that is engaged with the other flywheel side and is filled with liquid so as to be able to pass through the orifice plate, and is further provided with a mechanism that changes the diameter of the orifice so that the mechanism can be moved in the axial direction of the orifice. A torque fluctuation absorbing flywheel characterized by comprising a limit tube with a flange that can be brought into close contact with an orifice plate and can be separated from the orifice plate, and a coil wound around the orifice axis and assembled to the orifice plate.