JPS6017553Y2 - torsional damper - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a torsional damper used to suppress torsional vibration of a crankshaft of an internal combustion engine.

The crankshaft of an internal combustion engine is not a completely rigid body, but has a finite torsional spring constant, which generates torsional vibrations in the crankshaft in response to periodic torque fluctuations caused by engine rotation, resulting in mechanical noise and crankshaft breakage. It is the cause of

As a countermeasure to this problem, a torsional damper has conventionally been attached to the tip of the crankshaft to suppress torsional vibration.

As a typical conventional torsional damper, for example, as shown in FIG. 1, there is a damper in which an annular inertia mass 4 is attached to a disk plate 2 fixed to the tip of a crankshaft 1 via an elastic body 3. .

That is, when periodic torque fluctuations are applied to the crankshaft 1, the natural frequencies of the inertia mass 4 and the elastic body 3 are set to resonate or be close to resonance with the period (frequency) of the torque fluctuations. Therefore, the inertia mass 4 causes resonance, and as a result, the torsional vibration of the crankshaft 1 is suppressed.

Furthermore, by using rubber as the elastic body, the effect of suppressing torsional vibrations is increased due to internal viscous friction.

However, in the conventional structure that attempts to suppress torsional vibration by resonance of the elastic body 3, when the periodic torque fluctuations applied to the crankshaft 1 become large, especially when the engine is operated under high load, the disc plate 2 and the inertia mass 4 are damaged. The amount of relative rotation of the elastic body 3, that is, the amount of torsional deformation of the elastic body 3 becomes excessive, and the heat generated by the deformation significantly reduces durability, resulting in a significant shortening of the life of the torsional damper.

The present invention was made in view of the conventional situation,
By adding a friction damping mechanism to the above damper, the amount of torsional deformation of the elastic body is reduced, improving durability and significantly increasing the lifespan.The torsional damper also functions as a crank pulley and is more compact. It provides a damper.

The present invention will be explained in detail below based on embodiments shown in the drawings.

In FIG. 2, an inertia mass 4 is adhesively fixed to the periphery of a disc plate 2 fixed to a crankshaft 1 via an elastic body 3, and the outer surface of the inertia mass 4 is coated with a polymer resin having a small coefficient of friction. A membrane 4a is coated.

Specifically, a powdered polymeric resin material may be coated by a fluidized dipping method, an electrostatic coating method, or the like.

On the other hand, a crank pulley 5 having a V-groove 5a formed on its outer circumferential surface is fixed with screws 6 with its central portion overlapping the disc plate 2.

A notch 5b is formed in the peripheral edge of the side surface of the crank pulley 5 facing the inertia mass 4.

A pin 7 is provided protruding from the notch 5b in parallel with the axis of the crankshaft 1, and an intermediate ring 8 is inserted and attached to the pin 7 so as to be freely movable in the axial direction. An annular disc spring 9 is interposed and engaged between the two.

The spring constant of the disc spring 9 is set so that the disc spring 9 is compressed and the contact surfaces of the polymer resin film 4a of the intermediate ring 8 and the crank pulley 5 are brought into pressure contact with each other with an appropriate frictional force.
Set the shape etc.

With such a configuration, when torsional vibration occurs in the crankshaft 1, the disk plate 2 and crank pulley 5, which rotate together with the crankshaft 1, tend to cause torsional vibration.

Then, relative vibration occurs between the disc plate 2, the crank pulley 5, and the inertia mass 4.

Therefore, the elastic body 3 undergoes torsional deformation, and the contact surfaces between the polymer resin film 4a of the intermediate ring 8 and the peripheral portion of the crank pulley 5 undergo relative sliding rotation.

Therefore, both the viscous damping force accompanying the torsional deformation of the elastic body 3 and the amount of work required for mutual sliding between the contact surfaces of the polymer resin film 4a and the intermediate ring 6 (product of frictional force and relative sliding amount) As a result, torsional vibration of the crankshaft 1 is suppressed.

In other words, the damping function borne by the torsional deformation of the elastic body 3 can be reduced by the amount of work required for relative sliding between the polymer resin film 4a and the intermediate ring 6.

As a result, it is possible to use a material with a small viscous damping force, generally a soft material with spring rigidity, as the elastic body 3, so that the amount of heat generated by the viscous frictional resistance of the elastic body 3 is reduced.

On the other hand, due to the frictional resistance between the polymer resin film 4a and the crank pulley 5, the amount of torsional deformation of the elastic body 3 can be suppressed to a small level even when the engine is operated under high load.

Therefore, the durability of the elastic body 3 is greatly improved, and the life of the torsional damper can be significantly extended.

It is also conceivable to provide a friction damping mechanism in a notch formed on the inertia mass side, but in this case, in order to secure the mass of the inertia mass, the external shape of the inertia mass becomes large, and the damper as a whole becomes large. do.

On the other hand, if the crank pulley 5 is provided with a friction damping mechanism as in the present invention, there is no need to increase the external size of the inertia mass 4.

Furthermore, since the crank pulley 5 is used as a part of the damper as a mounting member for the friction damping mechanism, there is no need to provide a separate crank pulley, and the overall size can be significantly reduced.

Further, since vibration is intense on the inertia mass side, play is likely to occur in the friction damping mechanism, but this can also be suppressed by providing it on the rank boot IJ 5 side, where the vibration is relatively small.

In addition, in this example, only the contact surface part where sliding rotation occurs is formed of a polymer resin film, so it has good thermal conductivity and high heat dissipation efficiency, so deterioration of the elastic body can be suppressed from this aspect as well, and it is cost-effective. is also advantageous.

As explained above, according to the present invention, an intermediate ring is interposed between the crank pulley and the inertia mass, which are integrally fixed to the disc plate, and which presses against the inertia mass so that the inertia mass slides and rotates freely with frictional force. The work associated with sliding rotation can suppress the torsional vibration of the rotating shaft, and the damping force borne by the elastic body interposed between the inertia mass and the disk plate can be reduced accordingly. The amount of deformation can be reduced, and the durability and life of the torsional damper can be significantly improved.

Furthermore, since the friction damping mechanism is provided on the crank pulley with less vibration, reliability is excellent and miniaturization is also facilitated.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a conventional torsional damper, and FIG. 2 is a sectional view showing an embodiment of the torsional damper according to the present invention. DESCRIPTION OF SYMBOLS 1...Crankshaft, 2---Disc plate, 3...Elastic body, 4...Inertia mass, 4a...Polymer resin Membrane, 5...
・・・Crank pulley, 6... Screw, 7...
・Zen, 興...Middle ring, 9...Disc spring.

Claims (1)

[Scope of utility model registration request] In a torsional damper formed of a disk plate fixed to the end of a crankshaft of an internal combustion engine and an inertia mass fixed to the disk plate via an elastic body, the inertia mass is disposed between the inertia mass and the elastic body. While fixing the clamping crank pulley to the disc plate,
An annular notch is formed on the side surface of the crank pulley on the inertia mass side, and a hole is inserted into a pin fixed to the notch to provide an intermediate ring which is fixed so as to be freely movable only in the axial direction of the crankshaft. What is claimed is: 1. A torsional damper comprising: a disc spring that freely slides and presses the inertia mass in the rotational direction; and at least one of the contact surfaces between the intermediate ring and the inertia mass is coated with a polymer resin film.