JPH0620923Y2 - Flywheel with dynamic damper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a flywheel with a dynamic damper provided at a rear end portion of a crankshaft of an internal combustion engine.

[Prior Art] Usually, a flywheel attached to a rear end portion of a crankshaft of an internal combustion engine is configured as a disk-shaped object having a relatively large weight. However, in the structure in which the flywheel, which is simply a disc, is directly connected to the rear end of the crankshaft, as shown in FIG. 4, bending pressure occurs in the crankshaft 2 due to combustion pressure in the cylinder, especially in the cylinder 1 at the rearmost end, Surface runout occurs in the flywheel 3. This bending vibration is transmitted to the cylinder block and is a major cause of engine vibration.

A flywheel with a dynamic damper is conventionally known as a structure capable of suppressing the vibration of the flywheel. For example, in Japanese Utility Model Application Laid-Open No. 61-123241, a flywheel disk is connected to a rear end of a crankshaft via a flexible plate, and an annular damper mass is provided in the vicinity of an outer peripheral portion of the disk via a vibration isolating member in a rotation axis direction. There is disclosed a structure provided so as to be displaceable.

[Problems to be Solved by the Invention] However, in the structure disclosed in the above publication, since the annular damper mass is connected to the flywheel main body side through the vibration isolating member over the entire circumference, the mass of the damper mass is Works evenly on the wheel body side.
The surface runout of the flywheel mainly occurs when the combustion pressure is applied to the rearmost cylinder as shown in FIG. 4. However, in the structure described above, the flywheel has a dynamic damper effect in the surface runout direction. The mass of the damper mass is mainly the mass of the part in the combustion pressure acting direction. Therefore, even if the entire annular damper mass has a large mass, only a part thereof acts to suppress the runout of the flywheel surface, resulting in poor efficiency and therefore a small suppressing effect.

Further, since the flywheel body is connected to the crankshaft via the flexible plate, even if the vibration of the flywheel can be suppressed by the dynamic damper effect, the suppressing force is hardly transmitted to the crankshaft. Therefore, there is almost no effect of suppressing crankshaft bending vibration.

The present invention pays attention to such problems of the prior art, and efficiently exerts a dynamic damper effect and transmits the suppression force to the crankshaft when it is most necessary for suppressing the surface runout of the flywheel. By achieving this problem, it is an object to effectively reduce the contact of the flywheel, reduce the bending vibration of the crankshaft, and further reduce the engine vibration.

[Means for Solving the Problems] A flywheel with a dynamic damper according to the present invention which meets the above-mentioned object is concentric with the flywheel body on the crankshaft side of the flywheel body attached to the rear end of the crankshaft of the internal combustion engine. A disk-shaped plate provided with an annular mass is fixed, and the plate is positioned symmetrically with respect to the center of the flywheel at the uppermost cylinder of the engine at the bottom dead center direction.
Forming a corrugated undulation extending in a direction perpendicular to the direction of the bottom dead center, fixing the annular mass to a position outside the corrugation of the plate, and inside the corrugation of the annular mass and the plate. It consists of a part with a gap.

[Operation] In such a flywheel, the corrugated undulations are formed on the disc-shaped plate, whereby the rigidity of this portion is reduced, and the outer portion is easily displaced with respect to the inner portion of the undulation. The plate with the undulations constitutes the spring system of the dynamic damper, and the annular mass fixed to the outer part of the undulation constitutes the mass of the dynamic damper. Since the undulations are formed on the rearmost cylinder at symmetrical positions in the direction of the bottom dead center, and in the direction perpendicular to the direction of the bottom dead center, the dynamic damper is configured in the surface runout suppressing direction of the flywheel body. It Since the annular mass is fixed only to the outer side of the corrugation and has a gap between it and the plate in other parts, the flywheel surface runout suppression direction is in the vibration direction of the plate as the spring system of the dynamic damper. And the entire mass of the annular mass acts on the outer part of the undulations, maximizing the dynamic damper effect within the limited shape and space, and making the runout of the flywheel body efficient. Well suppressed. Since the flywheel main body is directly connected to the rear end portion of the crankshaft, the efficiently suppressing force also acts as the bending vibration suppressing force of the crankshaft.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

1 to 3 show a flywheel with a dynamic damper according to an embodiment of the present invention. In the drawing, reference numeral 11 denotes a crankshaft rear end portion of an internal combustion engine, and a disk-shaped flywheel main body 12 having a relatively large weight is bolted to the crankshaft rear end portion 11. On the crankshaft 11 side of the flywheel main body 12, a relatively thin disk-shaped plate 13 concentric with the flywheel main body is fixed via bolts.

The plate 13 has corrugated undulations 15 formed at symmetrical positions with respect to the flywheel center 14. The waveform undulations 15 are located at symmetrical positions with respect to the center 14 of the flywheel 14 at the rearmost cylinder of the engine (shown in FIG. 3) with respect to the bottom dead center direction X-X. It extends to the edge of the plate 13 in a direction substantially perpendicular to X. Here, the last cylinder of the engine is the cylinder closest to the flywheel,
For example, in the case of an in-line 4-cylinder engine, it is No. 4 cylinder.

An annular mass 17, which is concentric with the main body 12 and has a relatively large weight, is fixed to the plate 13 by a method such as welding. Annular mass
17 is a part 13a on both outer sides of the corrugation 15 of the plate 13.
A gap 18 is fixed between the annular mass 17 and the portion 13b that is fixed to the plate 13 and that is inside the corrugated relief 15.

The plate 13 is made of a metal plate, and a vibration damping material 19 made of, for example, rubber is attached to the concave portion of the corrugated undulations 15 by a method such as pasting.

20 indicates a ring gear.

The operation of the embodiment apparatus configured as described above will be described.

By forming the corrugated undulations 15 on the plate 13, since the rigidity of the portion is reduced, both outer side portions 13a are displaced (deformed) with respect to the portion 13b inside the corrugated undulations 15 fixed to the flywheel body 12. ) Is easier and the spring is constructed. Annular masses 17 are fixed to both outer side portions 13a, and the corrugated undulations 15 are located on the rearmost cylinder 16 with respect to the flywheel center 14 at a position symmetrical with respect to the bottom dead center direction, and in a direction perpendicular to the bottom dead center direction. Since it extends, the plate 13 constitutes a spring system of the dynamic damper in the plane wobbling direction YY of the flywheel main body 11, and the annular mass 17 constitutes the mass of the dynamic damper. Further, since the plate 13 is a metal plate, it has a small damping function, but since the vibration damping material 19 is provided in the corrugated undulation 15 part, the damping function for obtaining the dynamic damper effect in a wide range of frequencies by the vibration damping material 19. Is obtained. Since the vibration damping material 19 is provided in the corrugated undulations 15 having the largest bending deformation amount, the vibration damping material 19 itself can be largely deformed, so that the function thereof is further enhanced. That is, the corrugated undulations 15 of the plate 13, the vibration damping material 19, and the annular mass 17 have a spring system, a damping function, and a mass function of the dynamic damper, respectively, and constitute a dynamic damper that reduces the vibration of the flywheel body 12. .

In this dynamic damper, the annular mass 17 is fixed only at the portion 13a on the outer side of the corrugated undulations 15 of the plate 13, and a gap is provided between the annular mass 17 and the plate 13 at the portion between them. Directionality of vibration is imparted to the fixed portion. That is, it is the surface wobbling direction of the flywheel body 12. Therefore, the dynamic damper works in the direction of suppressing the surface runout of the flywheel body 12. Further, since the fixed portion of the annular mass 17 is only the outer side portions 13a, the total mass of the annular mass 17 as the dynamic damper mass acting on the spring system (plate 13) is the outer side portions 13a.
You will concentrate on a. Therefore, the mass of the dynamic damper can be maintained large, the dynamic damper effect is improved accordingly, and the flywheel body 12
Surface wobbling is effectively suppressed.

Further, since the dynamic damper is configured while maintaining the structure in which the flywheel main body 12 is directly connected to the crankshaft rear end portion 11, suppression of surface runout of the flywheel main body 12 directly suppresses bending vibration of the crankshaft 11. Leads to. That is, as schematically shown in FIG. 3, the bending vibration of the crankshaft 11 caused by the combustion pressure acting at the top dead center of the rearmost cylinder 16 and the accompanying surface runout of the flywheel body 12 are caused by the plate 13, the waveform. It is effectively reduced by the dynamic damper constituted by the undulations 15 and the annular mass 17.

[Effects of the Invention] As described above, when the flywheel with a dynamic damper of the present invention is used, regarding the direction in which the combustion pressure of the rearmost cylinder, which is the main cause of the bending vibration of the crankshaft and the surface runout of the flywheel, acts. The dynamic damper can be configured efficiently, and the direct connection structure between the flywheel body and the rear end of the crankshaft can be maintained as it is, so both bending vibration of the crankshaft and surface runout of the flywheel are efficiently reduced. It is possible to reduce engine vibration.

Further, in the dynamic damper system configured, since the mass of the annular mass is effectively concentrated in a necessary portion of the spring system, the annular mass has a limited weight to be stored in a limited space, It is possible to maximize the dynamic damper effect.

Furthermore, since the spring system can be configured by simply forming the corrugated undulations on the plate, the desired dynamic damper can be configured with a simple structure and a small space.

[Brief description of drawings]

1 is a sectional view of a flywheel with a dynamic damper according to an embodiment of the present invention, a sectional view taken along the line I-I of FIG. 2, and FIG. 2 is a view from the crankshaft side of the flywheel of FIG. A side view as seen, FIG. 3 is a schematic diagram showing the operating principle of the apparatus of FIG. 1, and FIG. 4 is a schematic configuration diagram of a conventional flywheel and crankshaft. 11 …… Crankshaft rear end 12 …… Flywheel body 13 …… Plate 13a …… Outside part 13b …… Inside part 14 …… Flywheel center 15 …… Wave undulation 16 …… End cylinder 17 …… Circular mass 18 …… Gap 19 …… Vibration damping material XX …… Uppermost cylinder, bottom dead center direction YY …… Surface deflection direction

Claims (1)

[Scope of utility model registration request] 1. A crankshaft side of a flywheel main body attached to a crankshaft rear end portion of an internal combustion engine,
A disc-shaped plate provided with an annular mass concentric with the flywheel main body is fixed, and the plate is placed at a position symmetrical with respect to the center of the flywheel at the rearmost cylinder of the engine at the bottom dead center direction. A corrugated undulation extending in a direction perpendicular to the point direction is formed, and the annular mass is fixed to a portion outside the corrugation of the plate, and between the annular mass and a portion inner than the corrugation of the plate. Is a flywheel with a dynamic damper characterized by having a gap.