JP2000145891A - Flexible plate and flywheel assembly using flexible plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb the bending vibration of a crank shaft in good performance and reduce noise emission at accelerating while the clearness in clutch disengagement is well maintained. SOLUTION: A flexible plate 4 consists of a disc in which the end of a piston on the side receiving a load resulting from the bending vibration is cut off partially in the circumference, and has cut edges 4e and 4f. Accordingly the diameter of the piston on the side receiving the load resulting from the bending vibration is smaller than the diameter on the other side, and therefore, the bending rigidity of the piston on the side receiving the load resulting from the bending vibration is smaller than the bending rigidity on the other side. Thus the resultant flexible plate 4 has an anisotropic bending rigidity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flywheel assembly and a flexible plate as a component thereof.

[0002]

2. Description of the Related Art A combustion force of an engine is converted into a rotational force by a crankshaft. At this time, bending vibration occurs on the crankshaft. This bending vibration is transmitted to the flywheel assembly mounted on the end of the crankshaft, and the flywheel assembly vibrates, and the reaction force excites the vehicle body via the engine block and the engine mount. This is the noise during acceleration.

[0003] In order to reduce such noise during acceleration, it is effective to reduce the vibration of the flywheel assembly. Therefore, conventionally, a flexible plate is provided between the flywheel and the crankshaft. This flexible plate has an inner peripheral portion fixed to the crankshaft end and an outer peripheral portion fixed to the flywheel. Since the flexible plate absorbs bending vibration of the crankshaft, vibration of the flywheel is reduced, and noise during acceleration is reduced.

[0004]

In order to reduce the above-mentioned bending vibration, the effect becomes smaller as the rigidity of the flexible plate in the bending vibration direction of the crankshaft becomes lower. But,
If the rigidity is too low, the flywheel may move in the axial direction when the clutch is released, and the clutch may be less easily disengaged.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flexible plate and a flywheel assembly capable of better absorbing the bending vibration of a crankshaft and further reducing noise during acceleration while maintaining good clutch disengagement. It is in.

[0006]

According to a first aspect of the present invention, there is provided a flexible plate disposed between a crankshaft of an engine and a flywheel, wherein the flexible plate is mounted on the flywheel. A disk-shaped member having a wheel mounting portion and an inner peripheral center portion mounted on the crankshaft, wherein the disk member is partially cut on an outer peripheral portion so as to generate anisotropy in bending rigidity; Is missing.

[0007] The bending vibration generated on the crankshaft by the engine is transmitted to the flywheel side. At this time, the flexible plate is elastically deformed and absorbs bending vibration of a predetermined range of frequency and amplitude. Thereby, the flexible plate plays a role of insulating transmission of bending vibration of the crankshaft to the flywheel in a predetermined range.

[0008] The bending vibration generated on the crankshaft is generated on a surface having a certain angle with respect to the crank throw of the engine piston. That is, the force due to the bending vibration of the crankshaft acting on the flexible plate acts in the direction of this surface, and the range of vibration that can be absorbed is determined mainly by the radial bending rigidity of the flexible plate corresponding to this surface. On the other hand, the rigidity in the axial direction (translational rigidity) of the flexible plate that affects the disengagement of the clutch is a combination of all radial rigidities of the flexible plate.

In a conventional flexible plate, the bending stiffness in all radial directions is the same. That is, since the bending stiffness is isotropic, there is a strong correlation between the bending stiffness that affects the absorption of the bending vibration of the crankshaft and the translation stiffness that affects the disengagement of the clutch. However, the vibration damping property of the bending vibration and the disengagement property of the clutch are basically contradictory to each other.

In the flexible plate of the present invention, since the bending stiffness has anisotropy, the bending stiffness in the radial direction of the flexible plate which affects the absorption of the bending vibration of the crankshaft while maintaining the translational stiffness is reduced. Becomes possible. This makes it possible to better absorb the bending vibration while maintaining the disengagement of the clutch satisfactorily. In addition, since the translational rigidity and the bending rigidity can be set independently, the resonance frequencies (natural frequencies) of the two modes of translation and bending of the flywheel assembly including the flywheel and the flexible plate are positively separated. And the vibration damping of the flywheel assembly is improved.

In the flexible plate according to the second aspect, the bending rigidity in the direction in which the disk member receives a load due to the bending vibration of the crankshaft is smaller than the bending rigidity in the other directions. I have.

According to a third aspect of the present invention, in the flexible plate according to the first or second aspect, in the disk member, a diameter in a direction of receiving a load due to bending vibration of the crankshaft is shorter than a diameter in another direction. It is a flexible plate of description.

According to a fourth aspect of the present invention, there is provided a flywheel assembly according to any one of the first to third aspects, wherein a flywheel to which a clutch device can be attached and the flywheel mounting portion are fixed to the flywheel. And a plate and a flywheel assembly.

[0014]

FIG. 1 shows a flywheel assembly 1 and a clutch device 2 mounted on the flywheel assembly 1 according to one embodiment of the present invention.

The flywheel assembly 1 is mounted on the end of the crankshaft 3 of the engine E, and includes a flexible plate 4 and a flywheel 5.

The flexible plate 4 has a hole 4a at the center.
It is formed in a disk shape having The inner peripheral portion (central portion) 4b is provided with a bolt 6
It is fixed by. A hole 10 is provided in the inner peripheral portion 4b of the flexible plate 4 near the outer peripheral side of the hole 4a, and the bolt 6 passes through the hole 10. Outer peripheral portion (flywheel mounting portion) 4c of flexible plate 4
Is provided with a bolt 11, and the bolt 7 passes through the hole 11 and is fixed to the outer peripheral side surface of the flywheel 5.
As a result, the crankshaft 3 and the flywheel 5 are connected by the flexible plate 4 so that they cannot rotate relative to each other.

The flywheel 5 is a substantially disk-shaped member, and has a friction surface 5a on the side opposite to the flexible plate 4.
have.

The clutch device 2 includes a clutch cover assembly 20 and a clutch disk assembly 21 disposed in the clutch cover assembly 20. The clutch cover assembly 20 includes a clutch cover 22 fixed to an outer peripheral portion of the flywheel 5, a pressure plate 23 for holding the clutch disc assembly 21 between the friction surface 5a of the flywheel 5, and a pressure plate 23. A diaphragm spring 24 for pressing the flywheel 5 is provided. The center of the clutch disk assembly 21 is slidably connected to the input shaft of a transmission (not shown) in the axial direction. The inner peripheral end of the diaphragm spring is connected to a release bearing (not shown).

As shown in FIG. 2, the flexible plate 4 has cut sides 4e and 4f at both ends in the y-axis direction. That is, the flexible plate 4 is not exactly a disk shape but has a state in which both ends in the y-axis direction are cut out.

Here, the y-axis is the direction of the bending vibration of the crankshaft 3 accompanying the combustion of the engine E. The x-axis is an axis orthogonal to the rotation axis of the crankshaft 3 and the y-axis. In this embodiment, the surface of the crankshaft 3 where bending vibration occurs is defined as y
The crankshaft 3 and the flexible plate 4 are fixed so as to match the axis. As a result, the crankshaft 3
It is the bending stiffness around the x axis that affects the absorption of bending vibration between the flywheel 5 and the flywheel 5. Here, the bending stiffness around the x-axis is the bending stiffness of a plane parallel to the x-axis in the direction of rotation about the x-axis.

As a result of the notch in the y-axis direction in the flexible plate 4, the bending rigidity here has anisotropy. That is, in this embodiment,
Since the flexible plate 4 has the cut sides 4e and 4f, the bending rigidity of the flywheel 5 fixed to the flexible plate 4 around the x axis with respect to the crankshaft 3 is:
The bending rigidity around the y-axis, which does not significantly affect the absorption of bending vibration, is relatively low.

FIG. 3 shows the measured values of the change in bending stiffness. Figure 3
Is a correlation graph of the ratio of the cutting width a / radius r to the plate thickness t. From FIG. 3, it can be seen that the larger the cutting width a, the lower the bending rigidity of the flexible plate 4 as a whole, and to compensate for this, the larger the plate thickness t, the better. In FIG. 3, t ₀ is the value of the plate thickness t when the flexible plate has a disk shape.

FIG. 4 shows actually measured values showing the correlation between the ratio of the cutting width a / radius r and the resonance frequency (natural frequency) fny around the y-axis. Here, the resonance frequency f around the x-axis
The plate thickness t is changed so that nx becomes constant. FIG.
As is clear from FIG. 4, the resonance frequency fny around the y-axis increases as the cut width a increases.

As is clear from the experimental results shown in FIGS. 3 and 4, in this embodiment, the flexible plate 4
Since the bending rigidity of the flexible plate 4 has anisotropy, the cutting width a is increased while adjusting the plate thickness t, so that the resonance frequency around the x-axis can be maintained while maintaining the translational rigidity of the flexible plate 4 as a whole. fnx and the resonance frequency (natural frequency) fny around the y-axis can be changed.

Further, as compared with the case of the conventional disk-shaped flexible plate, the provision of the cut sides 4e and 4f also has the effect of improving the yield of the plate in the manufacturing process.

Next, the operation will be described.

The combustion of the engine generates a rotational force on the crankshaft 3 and generates bending vibration. This rotational force and bending vibration are transmitted to a flexible plate 4 fixed to the crankshaft 3. The rotational force is transmitted from the flexible plate 4 to the flywheel 5, and then the clutch disc assembly 2 held between the flywheel 5 and the pressure plate 23 by a clutch operation.
1 and further transmitted (not shown)
Is transmitted to. On the other hand, the bending vibration of the crankshaft 3 is low due to the low rigidity of the flexible plate 4 in the y-axis direction.
It is well absorbed by the flexible plate 4. Further, when the translational rigidity is made equal, the resonance frequency f is lowered by the notch of the flexible plate 4, so that the resonance frequency can be set so as to be out of a normal frequency range in which resonance is a problem in the vehicle. Excitation of the vehicle body is suppressed, and noise during acceleration is reduced. Since the translational rigidity can be maintained relatively high, the disengagement of the clutch is good. (Other Embodiments) In the above embodiment, as shown in FIG. 2, the flexible plate 4 having the same cutting width a at both ends of the y-axis is employed. The line may not be orthogonal to the y-axis, or may be cut off on only one side. As an example, FIG. 5 shows a flexible plate 14 in which cut lines at both ends of the y-axis are not parallel, and FIG. 6 shows a flexible plate 24 which is cut out on only one side.

In the embodiment shown in FIG. 5, when the rotation axis of the crankshaft 3 is the z-axis, the moment about the z-axis of the flexible plate around the point where the x-axis and the y-axis intersect is not isotropic. However, since the weight of the flexible plate is smaller than the weight of the flywheel, there is almost no effect on transmission of rotational force to the flywheel.
This is the same in the embodiment of FIG. In each of the examples of FIGS. 5 and 6, the other configuration is the same as that of the above-described embodiment. The flexible plate 14 in FIG. 5 has a hole 14a at the center and is formed in a substantially disk shape. The bolt 6 (FIG. 1) passes through a hole 15 provided near the hole 14a. The bolt 7 (FIG. 1) passes through a hole 16 provided in the outer peripheral portion 14c. At both ends in the y-axis direction of the flexible plate 14, cut sides 14e and 14f that are not orthogonal to the y-axis are provided.

The flexible plate 24 shown in FIG. 6 has a hole 24a at the center and is formed in a substantially disk shape. The bolt 6 (FIG. 1) penetrates a hole 25 provided near the hole 24a. The bolt 7 (FIG. 1) penetrates a hole 26 provided in the outer peripheral portion 14c. A cut side 24e is provided at one end of the flexible plate 24 in the y-axis direction.

Also in these embodiments, the bending stiffness has anisotropy, and the bending vibration can be more absorbed without lowering the disengagement of the clutch. Further, by positively changing the resonance frequency (natural frequency) of the two modes of translation and bending, the vibration damping performance of the flywheel assembly 1 is improved.

In the above three embodiments, the flywheel assembly 1 having no damper mechanism for attenuating the torsional vibration generated in the crankshaft 3 is used. The present invention can also be applied to a divided flywheel in which a wheel is divided and a damper mechanism is provided between them. Further, the present invention can be applied not only to the clutch type but also to a torque converter type vehicle.

[0032]

Since the flexible plate of the present invention has anisotropy in bending stiffness, it is possible to reduce bending stiffness in a certain direction while maintaining translational stiffness. As a result, while maintaining good clutch disengagement,
Bending vibration of the crankshaft can be better absorbed and noise during acceleration can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a flywheel assembly according to an embodiment of the present invention.

FIG. 2 is a plan view of a flexible plate.

FIG. 3 is a graph showing a correlation between a ratio of a cut width / radius and a plate thickness.

FIG. 4 is a graph showing a correlation between a ratio of a cutting width / radius and a resonance frequency (natural frequency) in a y-axis direction.

FIG. 5 is a plan view of a flexible plate according to another embodiment.

FIG. 6 is a plan view of a flexible plate according to still another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible plate assembly 3 Crankshaft 4 Flexible plate 5 Flywheel 4e, 4f Cut side 14 Flexible plate 14e, 14f Cut side 24 Flexible plate 24e Cut side

Claims (4)

[Claims] 1. A flexible plate disposed between a crankshaft of an engine and a flywheel, comprising a flywheel mounting portion on an outer peripheral side mounted on the flywheel, and an inner peripheral mounted on the crankshaft. A flexible plate, comprising: a disk-shaped member having a center portion on a side thereof, wherein the disk member is partially cut off on an outer peripheral side so as to cause anisotropy in bending rigidity. 2. The flexible plate according to claim 1, wherein the disk-shaped member has a smaller bending rigidity in a direction in which a load is applied by a bending vibration of the crankshaft than a bending rigidity in other directions. 3. The flexible plate according to claim 1, wherein a diameter of the disc-shaped member in a direction in which a load is applied by bending vibration of the crankshaft is shorter than a diameter in other directions. 4. A flywheel assembly comprising: a flywheel to which a clutch device can be attached; and the flexible plate according to claim 1, wherein the flywheel mounting portion is fixed to the flywheel. .