JP3243203B2 - Flexible flywheel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible flywheel attached to an output rotation shaft of an internal combustion engine,
In particular, the present invention relates to a motor mounted on a crankshaft of an automobile or the like for the purpose of suppressing vibration.

[0002]

2. Description of the Related Art A flywheel is attached to an end of a crankshaft used in an internal combustion engine, and the inertia of the flywheel is used to smoothly rotate the crankshaft. In the case where the flywheel vibrates due to vibration caused by a bending force or the like from a piston acting on the crankshaft, a flywheel called a flexible flywheel, such as that disclosed in Japanese Utility Model Laid-Open No. 6-51590, is used. Wheels are often used. This flexible flywheel has a structure in which a flywheel mass, which is a ring-shaped inertial member having a predetermined coefficient of inertia, is fixed to an elastically deformable disk-shaped flexible plate. And is attached to the crankshaft through the shaft. Thus, the vibration of the crankshaft is absorbed and attenuated by the elastic deformation of the flexible plate.

[0003]

However, even in this case, vibration may not be suppressed due to, for example, occurrence of resonance at a constant rotational speed. In order to solve such a problem, a flexible flywheel having a structure in which an elastically deformable disk-shaped damping plate is added has been considered. By adding a vibration-damping plate smaller than the flexible plate, the rigidity of the flexible flywheel is locally increased, the rotational speed at which resonance occurs is out of the normal range, and the vibration prevention effect of the flexible flywheel is added. Is designed so as not to significantly impair.

[0004] However, conventionally, in order to obtain an optimal elastic damping plate, for example, in order to cope with various engines, it has been necessary to change the thickness and material of the damping plate. As a result, standard materials cannot be used, which not only imposes a large load on the production of the damping plate, but also increases the production cost and makes it impossible to cope with fine tuning of elasticity. was there.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an elastically deformable vibration damping plate having a plurality of through holes formed therein. The purpose of the present invention is to provide a flexible flywheel that can be easily tuned to obtain a vibration prevention effect and does not cause difficulty in manufacturing and increase in manufacturing cost.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a flexible flywheel attached to an output rotary shaft of an internal combustion engine, comprising a flexible plate capable of elastic deformation and a ring-shaped fly having a predetermined coefficient of inertia. Wheel mass,
An elastically deformable vibration damping plate, wherein the vibration damping plate is provided with a plurality of through holes having the same shape in point symmetry with respect to the center thereof, and the number of through holes having the same shape is formed. Is set to an odd number excluding a multiple of the number of cylinders of the internal combustion engine.

In such a case, the elasticity can be easily and finely tuned by changing the shape, size, number and the like of the through holes without changing the material and thickness of the damping plate. be able to. Therefore, it is possible to easily add an optimum vibration suppression function corresponding to various engines and members without incurring complicated manufacturing or increasing costs. Further, since the through holes are formed point-symmetrically with respect to the center of the vibration damping plate,
Uniform bending such as a bowing sound can be prevented by bending evenly against the load from the clutch. Further, since the number of the through holes is odd and set to a number excluding a multiple of the number of cylinders of the internal combustion engine, the number of the through holes is symmetrical with respect to the periodic vibration in the rotational direction and the axis which acts in accordance with the number of cylinders. In synchronization with the bending vibration. That is, as compared with a conventional vibration damping plate having no through hole and having the same elasticity, it is possible to reduce the resonance magnification with respect to the vibration transmitted from the rotating shaft, thereby providing a favorable Vibration damping can be performed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the flexible flywheel according to the present embodiment has an elastically deformable flexible plate 1, a compression plate 2 as an elastically deformable vibration damping plate having a smaller radius than the flexible plate 1, and an inertia member. A flywheel mass 3 is attached to, for example, a crankshaft 4 which is an output rotating shaft of an automobile engine such as an internal combustion engine (not shown). In the present embodiment, for example, a three-cylinder engine is employed as this engine.

The crankshaft 4 is generally known for converting the vertical movement of the piston in each cylinder of the engine into rotation and outputting the rotation.
a is provided with a columnar projection 41, and this projection 41
, A plurality of female screw holes 42 are formed point-symmetrically with respect to the axis, and a reamer hole 43 for a knock pin is formed at one place.
Is provided.

The flexible plate 1 has a flat disk shape in this embodiment. As shown in FIGS. 1 and 4, a mounting hole 11 for fitting the projection 41 of the crankshaft 4 is provided at the center thereof. And the crankshaft 4
In the part corresponding to the female screw hole 42 and the reamer hole 43,
Each has a bolt insertion hole 12 and a reamer hole 13. In addition, a plurality of bolt insertion holes 14 are provided in the outer edge portion symmetrically with respect to the center.

As shown in FIGS. 1 to 3, the compression plate 2 is made of, for example, a leaf spring material, and has a flat disk-shaped center member 2A and an edge member 2B integrally formed on the outer edge of the center member 2A. It consists of and. The center member 2A is provided with a mounting hole 21 at the center thereof to be fitted into the projection 41 of the crankshaft 4, and a bolt insertion hole is provided in a portion corresponding to the female screw hole 42 and the reamer hole 43 of the crankshaft 4, respectively. 22 and reamer hole 2
3 is provided. The edge member 2B is formed so as to be bent obliquely from the outer edge of the center member 2A and extend outward. In the present embodiment, for example, five circular through holes 7 and 5 are symmetrical with respect to the center of the center member 2A.
And two oblong through-holes 8 are formed so that these through-holes 7 and 8 are adjacent to each other.

As shown in FIGS. 1 and 5, the flywheel mass 3 is a ring having a predetermined coefficient of inertia.
A female screw hole 32 is provided in a portion near the outer periphery corresponding to the bolt insertion hole 14 of the flexible plate 1.
In addition, on the surface of the female screw hole 32 side, near the center hole 31,
Its outer diameter is larger than the outer diameter of the compression plate 2, and its depth dimension 34t is
Is provided slightly smaller than the height dimension of.

Next, an example of an assembling procedure will be described. In addition,
This procedure is merely an example, and the present invention is not limited to this procedure. Also, the procedure for assembling other parts is omitted. First, the flat washer 5 is fitted into the projection 41 of the crankshaft 4. As shown in FIG. 6, the flat washer 5 has, like the flexible plate 1, a mounting hole 51 at the center thereof to be fitted into the projection 41 of the crankshaft 4, a female screw hole 42 and a reamer hole 43 of the crankshaft 4. Are provided with bolt insertion holes 52 and reamer holes 53, respectively.

Next, the mounting holes 11 and 21 of the flexible plate 1 and the compression plate 2 are inserted into the projections 41 of the crankshaft 4 in this order, and the positions of the reaming holes 53, 13 and 23 are adjusted. And a knock pin 6 (a slotted spring pin in the case of the present embodiment).
And the flat washer 5, the flexible plate 1 and the compression plate 2 are fastened together to the crankshaft 4 by bolts 9A and mounted. At this time, the direction of the compression plate 2 is such that one surface 2A1 of the central member 2A is
It is set so as to make surface contact with a.

Next, after aligning the female screw hole 32 with the bolt insertion hole 14, the flywheel mass 3 is fastened to the flexible plate 1 with the bolt 9. At this time, the compression plate 2 is disposed in the recess 34, but since the depth 34t of the recess 34 is set to be slightly smaller than the height of the compression plate 2, the interference of the difference is reduced. Then, the compression plate 2 elastically deforms the edge member 2B,
The flywheel mass 3 and the flexible plate 1 are held in a state where the tip portion 2B1 is in contact with the bottom surface 34a of the concave portion 34.
Is pressed and clamped.

According to the flexible flywheel configured as described above, the shape and size of the through holes 7 and 8 can be reduced without changing the material and thickness of the compression plate 2.
By changing the number or the like, the elasticity can be easily and finely tuned, so that an optimum vibration suppressing function can be easily added without incurring complicated manufacturing or increasing the cost. In addition, since the through holes 7 and 8 are formed point-symmetrically with respect to the center of the compression plate 2, the through holes 7 and 8 are uniformly bent with respect to the load from the clutch 10 to prevent generation of abnormal noise such as a boring noise. I can do it. Further, since the through holes 7 and 8 are set to a number excluding a multiple of the number of cylinders of the engine, as shown in FIG. 3, a periodic external force M acting in the rotational direction corresponding to the number of cylinders is required. , The rigidity can be asymmetric so that synchronization is not achieved. Further, since the through holes 7 and 8 are set to odd numbers, the rigidity is asymmetrical to the bending vibration force F acting symmetrically with respect to the crankshaft 4 as described above, so that synchronization is not achieved. That is,
Compared with a compression plate having no through hole whose thickness is adjusted to have the same elasticity, a resonance magnification with respect to vibration transmitted from the crankshaft 4 can be reduced. It can perform a great vibration damping action. Particularly, in this embodiment, 2
Since through holes 7 and 8 having different shapes are formed to increase the number of through holes as a whole, stress can be effectively dispersed, and it is possible to contribute to improvement of durability and the like. It should be noted that the resonance magnification is a ratio of the amplitude amount to the static deflection amount, and it is understood that those having a low resonance magnification basically have a large vibration damping effect.

Further, as an effect peculiar to this embodiment, an increase in rigidity due to the addition of the compression plate 2 not only allows the rotational speed at which resonance is generated to be outside the normal range but also reduces the load from the clutch 10 side. Can be handled, and interference noise and baud noise can be prevented. However, since the compression plate 2 is made smaller than the flexible plate 1, the outer edge portion of the flexible plate 2 mainly bends against vibration, and the vibration damping is substantially the same as that of the case where only the flexible plate 2 is attached. You can expect properties. In addition, the compression plate 2 always moves in close contact with the flexible plate 2 irrespective of the swing of the flywheel mass 3 due to the elastic deformation given at the time of assembly. I do. Since the vibration damping effect obtained from the friction damping effect due to the surface friction can be expected, a sufficient vibration preventing effect of the flywheel mass 3 can be obtained. Further, since the compression plate 2 is held in a pressed state as described above, it is difficult for micro vibration to be generated on a contact surface with another member, which can contribute to improvement in fretting resistance. It is possible to prevent a phenomenon in which the mass 3 or the flexible plate 1 comes and comes close to and generates abnormal noise. Also, since there is no part that requires clearance management during assembly, it can contribute to an improvement in productivity.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the shape, number, size, and position of the through-holes are not limited to those in the embodiment, and the mounting method and shape of the compression plate, flywheel mass, and flexible plate are not limited to those in the embodiment. Further, the engine is not limited to a three-cylinder engine, and the same effect can be obtained even when the present invention is applied to an output rotary shaft of a rotary engine other than the engine.

In addition, the configuration of each section is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.

[0020]

As described above, according to the present invention, the shape, size, number, etc. of the through-holes can be changed easily and finely without changing the material and thickness of the vibration damping plate. Elasticity can be tuned. Therefore, it is possible to easily add an optimum vibration suppressing function in response to a change in the engine and other members without incurring complicated manufacturing or increasing costs. Further, since the through holes are formed point-symmetrically with respect to the center of the vibration damping plate, the through holes are uniformly bent with respect to the load from the clutch, thereby preventing occurrence of abnormal noise such as a boring noise. Further, since the through holes are set to a number excluding an even number and a multiple of the number of cylinders of the internal combustion engine, periodic vibrations in the rotational direction acting in accordance with the number of cylinders and bending acting symmetrically with respect to the axis. Not synchronized with vibration. That is, as compared with a conventional vibration damping plate having no through hole and having the same elasticity, it is possible to reduce the resonance magnification with respect to the vibration transmitted from the rotating shaft, thereby providing a favorable Vibration damping can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic vertical end view showing an internal structure of a flexible flywheel showing one embodiment of the present invention.

FIG. 2 is an enlarged front view of the compression plate in FIG. 1 as viewed from a crankshaft side.

FIG. 3 shows A- of the compression plate in FIG.
FIG.

FIG. 4 is a front view of the flexible plate in FIG. 1 as viewed from a crankshaft side.

FIG. 5 is a front view of the flywheel mass in FIG. 1 as viewed from the crankshaft side.

FIG. 6 is a front view of the flat washer in FIG. 1 as viewed from the crankshaft side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flexible plate 2 ... Compression plate (vibration suppression plate) 3 ... Flywheel mass 4 ... Rotation axis (crankshaft) 7, 8 ... Through-hole

Claims (1)

(57) [Claims] 1. A flexible flywheel attached to an output rotary shaft of an internal combustion engine, comprising: an elastically deformable flexible plate; a ring-shaped flywheel mass having a predetermined coefficient of inertia; A plurality of through holes having the same shape in point symmetry with respect to the center of the plate, and the number of the through holes having the same shape is an odd number. Wherein the number is set to a number excluding a multiple of the number of cylinders of the internal combustion engine.