JP2000266125A - Flywheel device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure durability of a flexible plate without spoiling an effect to reduce vibration and noise by a flywheel device with a flexible plate. SOLUTION: A disc type flexible plate 1 high in rigidity in the circumferential direction and low in rigidity in the diametrical direction is clamped by a pair of damping plates 2, 3 free to elastically deform having curved cross-section shapes, a part of the inner peripheral side of the flexible plate 1 is fastened on a shaft end of a crankshaft 5 with the damping plates 2, 3, and a specified part on the outside in the diametrical direction of the inner peripheral side part of the flexible plate 1 is clamped while pressurizing it from front and back by curved parts 24, 34 of a pair of the damping plates 2, 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flywheel device for an internal combustion engine having a flexible plate for transmitting torque and attenuating vibration in a bending direction.

[0002]

2. Description of the Related Art In internal combustion engines (engines) such as automobiles,
Attach the flywheel to the rear end of the crankshaft,
The shaft torque is averaged using the inertial force to achieve smooth rotation. However, in a high rotation region, a bending resonance phenomenon occurs from the rear portion of the crankshaft to the flywheel portion due to the mass-spring system from the crankshaft to the flywheel. The resonance frequency of this bending vibration is
When present in the high rotation range, unpleasant vibrations and noises are generated, giving a driver an unpleasant sensation, exacerbating clutch disengagement, and generating a large stress on the flywheel mounting portion of the crankshaft.

Therefore, in recent years, as shown in FIG.
And a flywheel device in which a flywheel 94 is mounted via a flexible plate 91 has been put to practical use. The flexible plate 91 is a disk-shaped member having high rigidity in the circumferential direction and low rigidity in the radial direction, and has an inner peripheral portion fixed to the rear end of the crankshaft 95 and an outer peripheral portion fixed to the flywheel 94. . By attaching the flexible plate 91, the bending rigidity of the entire flywheel device is reduced, and a resonance phenomenon of bending vibration is generated in a low rotation range, and engine vibration in a middle / high rotation range is reduced.
It suppresses noise, flywheel runout and crankshaft stress. Note that 92, 9
3 is an adapter plate.

[0004]

However, in the case of the flywheel device provided with the above-mentioned flexible plate 91, the overall vibration / noise, flywheel runout and crankshaft in the middle / high rotation range are provided by mounting the flexible plate 91. Is suppressed, but a resonance phenomenon occurs in the normal rotation range. As a result, the stress generated in the flexible plate 91 tends to concentrate particularly on the boundary between the flexible plate 91 and the mounting portion with the crankshaft 95, causing fatigue cracks and abrasion (fretting) on the mounting surface. There is a risk of doing so.

On the other hand, it is possible to increase the strength by increasing the thickness of the flexible plate, but the rigidity of the entire flywheel device is also improved, and the effect of reducing vibration and noise is reduced. . In addition, Japanese Patent Application Laid-Open
As disclosed in JP-A-144813, two disk-shaped plates of different materials are sandwiched between a flexible plate and a crankshaft, and the inner peripheral portion is fastened to the crankshaft together with the flexible plate with bolts,
A technique has been proposed in which the outer peripheral portion is fastened to the flexible plate with rivets. In this technique, the vibration of the flexible plate is suppressed by friction generated between the respective plates when the flexible plate is bent.

However, when both ends of the plate are fastened as in this technique, each plate bends integrally without sliding on the contact surface, and it is not possible to expect friction enough to absorb vibration energy. . Furthermore, depending on the material of the disc-shaped plate, for example, in the case of a soft material such as rubber, the flexible plate cannot be strongly fastened to the crankshaft, and there is a possibility that the flexible plate may be loosened due to vibration. In the case of a hard material such as metal, the rigidity of the entire flywheel device is improved, and the mounting effect of the flywheel device with the flexible plate is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been designed to ensure the durability of a flexible plate without impairing the vibration and noise reduction effect of a flywheel device with a flexible plate. It is an object to provide an engine flywheel device.

[0008]

In order to achieve the above object, in a flywheel device for an internal combustion engine according to the present invention, a pair of elastically deformable damping plates having a curved cross-sectional shape has high rigidity in a circumferential direction. A disk-shaped flexible plate with low rigidity is sandwiched in the radial direction, the inner peripheral side of the flexible plate is fastened together with the damping plate to the shaft end of the crankshaft, and a predetermined radial outside of the inner peripheral side of the flexible plate is fixed. The portion is sandwiched while being pressed from the front and back by the curved portions of the pair of damping plates.

Thus, the bending vibration of the flexible plate is suppressed by frictional resistance between the flexible plate and the curved portion of the damping plate.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a flywheel device for an internal combustion engine as an embodiment of the present invention.
FIG. 1 is a sectional view of a main part showing the configuration. FIG.
FIG. 3 is a diagram showing a configuration of a damping plate according to the present flywheel device.

As shown in FIG. 1, the present flywheel device has a configuration in which a flexible plate 1 having a flywheel 7 fixed on its outer periphery by bolts 6 is sandwiched between a pair of damping plates 2 and 3. . Insertion holes 2a and 3a are provided on the inner peripheral side of the damping plates 2 and 3 so as to correspond to the insertion holes 1a for the bolts 4 provided in the flexible plate 1. These insertion holes 1
The flexible plate 1 and the damping plates 2 and 3 are integrated with the crankshaft 5 by screwing the bolt 4 into the female screw hole 5a after aligning the positions of the a, 2a and 3a with the female screw hole 5a of the crankshaft 5. Is to be tightened together.

The damping plates 2 and 3 are made of an elastically deformable material (for example, S
K5M etc.), and as shown in FIGS. 1 and 2, is composed of mounting portions 21, 31 and a plurality of leaf springs 22, 32. The mounting portions 21 and 31 are provided with the above-described insertion holes 2.
a and 3a are provided, and are formed to be at least larger than the diameter of the crankshaft 5 and to be flat, and to be in close contact with the flexible plate 1 and the crankshaft 5 when the damping plates 2 and 3 are fastened. Has become.

On the other hand, the leaf springs 22 and 32
Plates extending radially from the base plates 1 and 31 at equal intervals. The radially extending surfaces of the plates are curved in an S-shape, and the two curved portions 23 and 2 projecting in opposite directions, respectively.
4, 33 and 34. Damping plate 2,
3 and the flexible plate 1 are fastened together
The inner curved portions 23, 33 are directed outward (opposite to the flexible plate 1), and the outer curved portions 24, 34 are positioned inside such that the outer curved portions 24, 34 sandwich the flexible plate 1. (The flexible plate 1 side).

Therefore, when the damping plates 2 and 3 are fastened to the crankshaft 5 with the flexible plate 1 interposed therebetween, the outer curved portions 24 and 34 come into contact with the flexible plate 1 and are displaced by receiving an outward force. The leaf springs 22 and 32 will bend. The bending generated in the leaf springs 22 and 32 is caused by the outer peripheral side curved portions 24 and
34 acts on the flexible plate 1 to press the flexible plate 1 and the outer peripheral side curved portions 24 and 34.
Are always in contact with the contact surfaces 25 and 35. The damping plates 2 and 3 have been subjected to a surface treatment such as a phosphate film treatment to improve the friction resistance.

The flywheel device for an internal combustion engine as one embodiment of the present invention is configured as described above.
When bending vibration occurs in the flexible flywheel Assy, the damping plates 2 and 3 that come into contact with the flexible plate 1 so as to be clamped also bend in accordance with the bending of the flexible plate 1.

For example, as shown in the sectional view of FIG. 3, when the flexible plate 1 is deformed clockwise in FIG. 3 in a vertical plane due to bending vibration of the flywheel 7 (FIG. 3 shows the deformation extremely). ), The leaf spring 32A above the damping plate 3 and the leaf spring 22B below the damping plate 2 are deformed so as to be pushed by the flexible plate 1. As a result, the contact surfaces 25B, 35A of the leaf springs 22B, 32A of the damping plates 2, 3 with the flexible plate 1 move outward while sliding on the flexible plate 1. At this time, since there is frictional resistance between the contact surfaces 25B, 35A and the flexible plate 1, frictional heat is generated by the frictional resistance associated with the movement of the contact surfaces 25B, 35A on the flexible plate 1.

On the other hand, the leaf spring 32B below the damping plate 3 and the leaf spring 22A above the damping plate 2
Means that the pressing force received from the flexible plate 1 is weakened due to the clockwise rotation of the flexible plate 1 so that the flexible plate 1 deforms to return to the initial position before the co-tightening, and follows the deformation of the flexible plate 1 in a clockwise direction. Deform to. Accordingly, the contact surfaces 25A, 35B of the respective leaf springs 22A, 32B of the damping plates 2, 3 with the flexible plate 1 move inward while sliding on the flexible plate 1, and the contact surfaces 25
Friction heat is also generated between A, 35B and the flexible plate 1 due to frictional resistance.

The same applies to the case where the flexible plate 1 is bent and deformed in other directions.
Between the contact surfaces 25 and 35 and the flexible plate 1 generates frictional heat based on frictional resistance. This frictional heat is
The energy of the bending vibration of the flexible plate 1 is converted into heat, and the vibration level of the flexible plate 1 is suppressed by converting the energy of the bending vibration into frictional heat. Therefore, even when the rotation speed of the engine enters the resonance region of the flexible plate 1, as shown in FIG. 4, the amplitude of the vibration of the flexible plate 1 is the same as when the damping plates 2 and 3 are mounted (see FIG. 4). (See the solid line)
3 is suppressed as compared with the case where no 3 is attached (see the dashed line in FIG. 4).

As described above, according to the flywheel device of the internal combustion engine, the vibration of the flexible plate 1 is attenuated by the frictional resistance between the flexible plate 1 and the damping plates 2 and 3. The bending vibration amplitude can be suppressed without increasing the thickness of the plate 1, and there is an advantage that the durability and reliability thereof can be ensured and the vibration and noise can both be reduced.

The mounting portion between the flexible plate 1 and the crankshaft 5 includes damping plates 2 and 3
There is also an advantage that the strength of the mounting portion is improved by fastening the mounting portions 21 and 31 together. further,
Since the flexible plate 1 comes into contact with the damping plates 2 and 3 not only at the attachment portion with the crankshaft 5 but also at the contact surfaces 25 and 35, the attachment portion with the crankshaft 5 having the stress accompanying bending deformation. Also, there is an advantage that the concentration can be eased, and the durability can be further improved.

It should be noted that the present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the spirit of the present invention. For example, in the above-described embodiment, the damping plates 2 and 3 are mounted symmetrically with respect to the flexible plate 1, but the circumferential positions of the contact surfaces 25 and 35 do not need to completely match. Instead, they may be staggered alternately. The same applies to the contact position in the radial direction. For example, the contact surface 25 may contact the outer peripheral side more than the contact surface 35, and vice versa.
In any of the above cases, the bending vibration of the flexible plate is attenuated due to the friction between the flexible plate and the damping plate, so that the vibration and noise are reduced and the durability reliability is secured.

The shape of the damping plate is not limited to the above-described embodiment, but can be variously modified and implemented. The inner peripheral portion of the flexible plate and the damping plate together with the shaft end of the crankshaft can be used. Any shape may be used as long as a predetermined portion radially outside the inner peripheral portion of the flexible plate can be sandwiched from the front and back by the curved portion of the damping plate.

For example, the damping plate 7 shown in FIG.
As shown in FIGS. 0 and 75, the plate springs 72 and 77 extending radially from the attachment portions 71 and 76 are provided with a plurality of curves, and the flexible plate 1 is sandwiched by the plurality of contact surfaces 73, 78, 74, and 79. Is also good. Further, as shown in FIG. 6, the damping plate 8 may be configured by connecting the mounting portion 81 and the contact portion 82 on the ring by a spring portion 83. That is, the contact portion 82 is formed by the spring portion 83.
Is pressed against the flexible plate so that the contact portion 82 comes into contact with the flexible plate at a predetermined surface pressure. According to such a configuration, the contact surface between the damping plate and the flexible plate is increased, thereby increasing the frictional resistance. Therefore, there is an advantage that the vibration of the flexible plate can be further damped.

Further, instead of sandwiching the flexible plate between the pair of damping plates as described above, the damping plate is attached to only one of the sides and fastened together, and the flexible plate is fastened together by this one damping plate. Alternatively, a predetermined portion radially outside the inner peripheral portion may be pressed. Even with such a configuration, suppression of bending vibration can be expected as compared with a flywheel device without a damping plate.

[0025]

As described above in detail, according to the flywheel device for an internal combustion engine of the present invention, the vibration of the flexible plate is attenuated by the frictional resistance between the flexible plate and the damping plate. Further, there is an advantage that bending vibration can be suppressed without increasing the thickness of the flexible plate, vibration and noise can be reduced, and durability and reliability thereof can be secured.

In addition, since the damping plate is fastened to the flexible plate together with the flexible plate, the stress generated in the flexible plate due to the bending deformation of the mounting portion of the flexible plate to the crankshaft can be reduced. There is also an advantage that reliability is ensured.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a main part of a configuration of a flywheel device for an internal combustion engine as one embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a damping plate according to the flywheel device of the internal combustion engine as one embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining the operation and effect of a flywheel device for an internal combustion engine as one embodiment of the present invention.

FIG. 4 is a diagram illustrating a relationship between frequency and amplitude for explaining the operation and effect of the flywheel device of the internal combustion engine as one embodiment of the present invention.

FIG. 5 is a sectional side view of a main part showing a modification of a damping plate according to a flywheel device of an internal combustion engine as one embodiment of the present invention.

FIG. 6 is a perspective view showing another modified example of the damping plate according to the flywheel device of the internal combustion engine as one embodiment of the present invention.

FIG. 7 is a side sectional view showing a configuration of a conventional flywheel device for an internal combustion engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible plate 2, 3 Damping plate 21, 31 Attachment part 22, 32 Leaf spring 23, 33 Bending part 24, 34 Bending part 25, 35 Contact surface 4 Bolt 5 Crankshaft 7 Flywheel

Claims (1)

[Claims] 1. A flywheel having a predetermined moment of inertia and a disk-shaped flexible plate having high rigidity in the circumferential direction and low rigidity in the radial direction, and the flywheel is connected to the engine via the flexible plate. A flywheel device for an internal combustion engine fixed to a crankshaft, comprising: a pair of elastically deformable damping plates having a curved cross-sectional shape; Along with the damping plate, together with the damping plate, the part is fastened to the shaft end of the crankshaft, and a predetermined portion of the flexible plate radially outside the inner peripheral side portion is pressed from the front and back by the curved portions of the pair of damping plates. Characterized by being sandwiched,
Flywheel device for internal combustion engine.