JPH0444914Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The disclosed technology is applied to bending of a pulley provided at the tip of a crankshaft installed in an automobile engine to operate an auxiliary machine such as a generator. It belongs to the technical field of crank damper pulley structures that dampen and absorb vibrations and suppress noise generation.

This invention is based on a mechanism in which the pulley hub of the pulley, which is installed at the tip of the crankshaft installed in the internal combustion engine of vehicles such as automobiles and which transmits power to auxiliary equipment such as an alternator via a belt, is removably fixed. This invention relates to a crank damper pulley structure that is equipped with a damper mass and damper rubber of a torsional damper set to absorb torsional vibration on the outer periphery of the crank damper pulley. A damping steel plate is fixedly installed, and damper rubber and damper mass forming a dynamic damper with a ring-shaped cross section set to absorb bending vibration are layered in the axial direction on the front surface of the damping steel plate. This invention relates to a crank damper pulley structure for a vehicle that is integrally attached by baking or the like.

<Prior Art> As is well known, automobiles are equipped with internal combustion engines such as gasoline engines, and the operation of reciprocating cylinders such as 4 cylinders and 6 cylinders is transmitted via a crankshaft to an axle shaft. On the other hand, auxiliary equipment such as an alternator is operated via a belt pulley mechanism.

It has long been known that a crankshaft receives an excitation force due to the inertial force of the engine and the explosive force of the cylinder, and is subjected to torsional vibration due to rotational motion.

Therefore, so-called torsional dampers are being provided to suppress vehicle body vibrations caused by the torsional vibrations and noise exerted on the interior of the vehicle.

It is technically difficult to install the torsional damper in the power transmission path to the axle side of the crankshaft due to the presence of complex mechanisms such as the flywheel. A pulley hub is provided that controls a pulley mechanism for transmitting power to an auxiliary machine such as a generator, and a torsional damper is provided by utilizing the relatively open mechanism of the pulley hub.

That is, as shown in FIG.
A pulley hub 3 is fitted onto the tip of the pulley hub 3 through a keyway or the like so that torque can be transmitted, and is fixed by a set bolt 2. Outside the pulley hub 3, there is a pulley hub 3 for transmitting power to auxiliary equipment such as an alternator. A damper mass 5 forming a belt notch 4 of the pulley is formed, and a damper rubber 6 is interposed integrally with the pulley hub 3 to form a torsional damper 7 configured to absorb torsional vibrations.

However, as is well known, crankshaft 1
It has also been found that in the above-mentioned four-cylinder, six-cylinder, etc. engines, bending vibrations are excited by inertial force and explosive force because the journals and crank pins are not attached axially symmetrically in the axial direction.

However, in conventional engines, not only the cylinder block but also the crankshaft are heavy and extremely rigid, so even if such bending vibrations are excited, the generated bending vibrations are not so great. Although it wasn't a big deal, recent efforts have been made to improve fuel efficiency and increase rotational power, so crankshafts have also been made lighter, which has led to an increase in horsepower. Over time, bending vibrations have become more prominent, and from the technical standpoint of suppressing vehicle body vibrations and noise prevention, there has been a strong demand for the provision of dynamic dampers to deal with the bending vibrations.

In other words, as shown in Figure 7, if we take the frequency of bending vibration on the horizontal axis and the amplitude of bending vibration on the vertical axis, we will get a graph in which the peak of the amplitude appears at a predetermined frequency of ₀ .
The characteristics of C ₁ appear, and as shown in Figure 8,
It has been found that one-node bending vibration Q ₁ and two-node bending vibration Q ₂ as shown in Fig. 9 appear.

In other words, the low-order bending vibration of the one-node bending or two-node bending
Q ₁ and Q ₂ excite the cylinder block, which not only causes vibrations to the vehicle body, but is also a major cause of noise generation in the vehicle interior.

Furthermore, when the bending vibration increases, a non-negligible problem has arisen in terms of the strength of the crankshaft itself.

<Problem to be solved by the invention> Therefore, in the conventional crank damper pulley structure as shown in FIG.
As disclosed in the patent publication No. 141256, the main focus is on the torsional damper function against torsional vibration, and there is a problem in that it is difficult to adapt the dynamic damper function to low-order bending vibration.

That is, for example, in the technology shown in Utility Model Application Publication No. 55-14139, although a damper rubber is provided in the pulley hub, a damper mass is not provided, and therefore, it is difficult to resist low-order bending vibrations. Since no damping function was provided, the damping function was not fully demonstrated.

In addition, in the damper pulley structure shown in Utility Model Application Publication No. 58-70554, the torsional damper function and the dynamic damper function are not differentiated, and the performance of the dynamic damper to absorb sufficient bending vibration is poor. There was a problem with the performance not being achieved.

The invention described in JP-A No. 59-40060 similarly places emphasis on the torsional damper function, and has the disadvantage that the dynamic damper function against bending vibrations is not fully utilized.

Furthermore, Utility Model Application Publication No. 58-50260, Utility Model Application Publication No. 58-58-
In the embodiment shown in the invention of Publication No. 33844, a technique is also shown in which a sound insulating plate is attached to the front side from the pulley hub to prevent radiated noise, but the sound insulating function is weak and the dynamic damper function is not satisfied.

In any of the conventional forms, the damper rubber of the dynamic damper does not have the function of absorbing bending vibrations, and even if it has a function equivalent to a dynamic damper that absorbs bending vibrations, it has a sound insulation function and the damper rubber of the dynamic damper. It did not have the function of preventing deterioration over time.

The purpose of this invention was to solve the technical problem of the crank damper pulley having a torsional damper function based on the above-mentioned conventional technology. It assists in reducing the weight of the crankshaft in order to improve fuel efficiency, and it also sufficiently damps and absorbs low-order bending vibrations, and does not cause deterioration of the bending damper. An object of the present invention is to provide an excellent crank damper pulley structure for a vehicle that is capable of suppressing forward-radiated noise from the pulley with a minimum number of additional parts, thereby benefiting the field of application of vibration and noise countermeasure technology in the automobile industry. It is.

<Means for solving the problem> In accordance with the above-mentioned purpose, the structure of this invention, which is based on the scope of the above-mentioned utility model registration claim, is to solve the above-mentioned problem. A crank damper pulley structure in which a pulley hub fixed via a set bolt has a damper mass and damper rubber of a torsional damper set to absorb torsional vibration, and the front open part of the pulley hub is connected to the torsion. A damping steel plate is fixedly installed to cover the lateral damper, and the damper rubber and damper mass of the dynamic damper are set to absorb bending vibration with a ring-shaped cross section along the axial direction of the crankshaft on the front side of the damping steel plate. It is a technological measure that has been added in a multi-layered manner.

<Function> Therefore, a dynamic damper is attached via a damping steel plate to the front surface of a pulley hub that is fixed via a set bolt to the end of a crankshaft attached to an internal combustion engine of a vehicle such as an automobile. To absorb forward radiated noise and also act as a dustproof cover, the damper rubber with a ring-shaped cross section of the dynamic damper and the pulley hub are fixed together in advance by baking or other means along the axial direction of the crankshaft. The torsional damper installed on the outside of the pulley hub is a dynamic damper that absorbs bending vibrations without any influence on each other, and absorbs low-order bending vibrations. It has good workability and is easy to maintain.

<Example> Next, an example of this invention will be described below based on FIGS. 1 to 5 with reference to FIG. 7.

Note that the same parts as those in the conventional mode shown in FIG. 6 will be described with the same reference numerals.

In the embodiment shown in FIGS. 1 and 2, a pulley hub 3 is removably inserted into the front end of a crankshaft 1 installed in an internal combustion engine of an automobile (not shown) via a set bolt 2 and a keyway, as in the conventional embodiment. , screwed and fixed.

The outside of the pulley hub 3 has a ring-shaped cross section and a belt groove 4 on the circumferential surface to form a torsional damper 7 against torsional vibration of the crankshaft 1, similar to the conventional embodiment shown in FIG. The damper mass 5 and the damper rubber 6 are stacked in the radial direction and are fixed together.

In this invention, the front surface of the pulley hub 3 has bolt holes 8, 8, . . . as shown in FIGS. 1 and 2.
...Bolts 9, 9... are drilled, as shown in Fig. 5.
A dynamic damper 10 that absorbs at least bending vibration is fixed to the front via...

Then, the dynamic damper 10 is connected to the third and fourth dampers.
As shown in the figure, a vibration damping steel plate 12 of the well-known Sanderch type is penetrated by bolt insertion holes 11, 11...
and a damper rubber 1 with a ring-shaped cross section on the front side of its periphery.
3 and a damper mass 14 of a predetermined size are layered in the axial direction by baking or other means, extended integrally, and fixed to the pulley hub 3 by bolts 9, 9, . . . .

In the above configuration, when the engine is operated,
As mentioned above, torsional vibration and low-order bending vibration occur in the pulley hub 3, but as shown in FIG. For vibrations, damping and absorption is performed in the same manner as in the past using the radial layer of damper mass 5 and damper rubber 6, and the torsional damper function is fully demonstrated.However, for low-order bending vibrations, Vibration is damped and absorbed by the damper rubber 13 and the damper mass 12, which are layered in the axial direction via the damping steel plate 12, and the amplitude is suppressed as shown in graph _C2 in Fig. 7. The peak of the _C1 graph is reduced, and vibration reduction and noise suppression are fully demonstrated.

Furthermore, the damping steel plate 12 also has the function of insulating and dissipating the heat generated in the pulley groove 4, thereby preventing the damper rubber 14 from deteriorating.

In this case, since the dynamic damper 10 is installed at the front of the pulley hub 3, the space can be used effectively, and its size can be freely designed to provide vibration damping and noise absorption for both torsional and bending vibrations. will be fully demonstrated together.

Therefore, noise caused by torsional vibration and low-order bending vibration tries to be emitted forward from the pulley hub 3 as so-called radiated noise, but it is absorbed by the damping steel plate 12 and is prevented from entering the vehicle interior, resulting in a quiet vehicle. You can get a good driving experience.

In addition, since the damping steel plate 12 has a kind of cover function for the damper pulley 3, it prevents moisture and dust from entering the pulley hub 3, and works effectively to prevent the set bolt 2 from rusting, so that it can be removed when replacing the pulley hub 3. It works so that it can be done easily.

Of course, the embodiments of this invention are not limited to the above-mentioned embodiments; for example, the damper rubber of a dynamic damper that absorbs bending vibrations or the damper mass may be made of a plurality of materials and divided in the circumferential direction. Various embodiments can be adopted, such as further providing another damper rubber and a damper mass at the center of the front surface of the damping steel plate.

<Effects of the invention> As described above, according to this invention, in addition to the torsional damper that has been installed in the pulley hub installed at the end of the crankshaft in the internal combustion engine of a conventional automobile, By installing a dynamic damper in the open part of the front part of the pulley hub that absorbs bending vibration by utilizing the free space in front of it, it basically absorbs torsional vibration as well as one-joint bending and two-joint bending. It has the advantage of being able to sufficiently damp and absorb (suppress) low-order bending vibrations such as bending, and therefore damp and absorb engine block vibrations and noise, ensuring quiet running. As a result, it is possible to reduce the weight of not only the engine block but also the crankshaft, helping to improve fuel efficiency, and also guaranteeing the strength of the crankshaft.

Secondly, the damping steel plate also functions as a kind of cover, has the function of preventing the torsional damper from coming off, and has the function of insulating the dynamic damper from the pulley. It has a heat insulating function, which prevents the damper rubber from deteriorating and maintains its function.

Furthermore, since the free space in front of the pulley hub can be actively utilized, a dynamic damper of optimal size can be created for damping and absorbing low-order bending vibrations in one-joint bending and two-joint bending. There is also the advantage of having a degree of freedom.

Thirdly, since the dynamic damper is attached to the open part at the front of the pulley hub via a damping steel plate that also covers the torsional damper, the damping steel plate has the effect of blocking sound radiated forward from the damper pulley. There is.

Therefore, as shown in Fig. 7, the amplitude of the curve _C1 , which has a peak of amplitude due to low-order bending vibration at a specific frequency in the conventional mode, is reduced as shown in the graph _C2 , and the amplitude is accurately This design has the excellent effect of suppressing engine vibration and noise.

Further, as described above, by utilizing the free space cavity in the front of the pulley hub, maintenance such as inspection and maintenance can be easily performed.

The damping steel plate also functions as a kind of cover and has the function of preventing the torsional damper from coming off.
It also has the function of insulating the dynamic damper from the pulley, preventing deterioration of the dynamic damper and maintaining its functionality.It also prevents moisture and dust from entering the set bolt and crankshaft of the pulley hub. It also has the synergistic effect of preventing rust and adhesion, and making it easier to remove.

[Brief explanation of drawings]

1 to 5 are explanatory diagrams of one embodiment of this invention, and FIG. 1 is a longitudinal sectional view of a torsional damper and a pulley hub provided at the tip of the crankshaft,
Fig. 2 is a front view of the same, Fig. 3 is a longitudinal sectional view of the dynamic damper, Fig. 4 is a front view of the same, Fig. 5 is a longitudinal sectional view of the pulley hub equipped with a torsional damper and a dynamic damper, and Fig. 6 is a longitudinal sectional view of the pulley hub equipped with a torsional damper and a dynamic damper. The figure is a vertical cross-sectional view of a torsional damper provided at the tip of a crankshaft in a conventional manner, FIG.
FIG. 9 is a schematic diagram of one-node bending vibration and two-node bending vibration of low-order bending vibration. 1... Crankshaft, 2... Set bolt, 3... Pulley hub, 14... Damper mass, 1
3... Bending damper rubber, 12... Vibration damping steel plate, 10... Dynamic damper.

Claims (1)

[Scope of utility model registration request] In the above-mentioned crank damper pulley structure, the pulley hub, which is fixed to the tip of the crankshaft of the vehicle engine through a set bolt, has a damper mass and damper rubber of a torsional damper that is set to absorb torsional vibration. A vibration damping steel plate is fixedly installed to cover the open part of the front part of the pulley hub over the torsional damper, and a ring-shaped cross section is attached to the front surface of the vibration damping steel plate along the axial direction of the crankshaft so as to absorb bending vibration. A crank damper pulley structure for a vehicle, characterized in that damper rubber and damper mass of a set dynamic damper are attached in a layered manner.