JPH0348435Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The disclosed technology is applied to a pulley that is installed at the tip of a crankshaft installed in an automobile engine and operates an auxiliary machine such as a generator. It belongs to the field of crank damper pulley structure technology that dampens and absorbs vibrations and bending vibrations.

This invention is based on a removably fixed pulley hub of a pulley that transmits power to an auxiliary device such as an alternator, which is installed at the end of a crankshaft installed in an internal combustion engine of a vehicle such as an automobile. This invention relates to a crank damper pulley structure that has a damper mass and damper rubber of a torsion damper around its periphery.In particular, it is designed to generate bending vibration with a circular cross section along the axial direction in a vagina drilled in the front part of the pulley hub. This invention relates to a crank damper pulley structure for a vehicle in which damper rubber and damper mass forming a dynamic damper are layered and integrally attached to a set bolt for attaching a pulley hub by baking or the like.

<Prior Art> As is well known, automobiles are equipped with internal combustion engines such as gasoline engines, and the reciprocating operation of four cylinders, six cylinders, etc. is transmitted to an axle shaft via a crankshaft on the one hand, and a pulley on the other. Auxiliary equipment such as an alternator is operated via the belt.

It has long been known that the crankshaft is subjected to 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 complicated mechanisms such as wheels. A pulley hub is provided that controls a pulley mechanism for transmitting power to an auxiliary device such as a turnator, and a torsional damper is provided around the pulley hub 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 of the pulley hub 3, there is a power supply to the auxiliary equipment such as the alternator. A damper mass 5 forming the belt notch 4 of the transmission pulley is attached, and a damper rubber 6 is interposed integrally with the pulley hub 3 to form a torsional damper 7.

By the way, as is well known, in the above-mentioned 4-cylinder, 6-cylinder, etc. engines, the crankshaft 1 has pins and journals that are not formed axially symmetrically, so bending vibrations are excited by the above-mentioned inertial force and explosive force. I knew that too.

However, in conventional engines, not only the cylinder block but also the crankshaft are heavy and extremely rigid, so even if the bending vibration is excited, the generated bending vibration is not that large. However, in recent years, crankshafts have been made lighter in order to address fuel efficiency issues and increase the precision of rotational power.However, this has combined with improvements in horsepower, etc., which has led to significant bending vibrations. As a result, there has been a strong demand for dynamic dampers that can deal with bending vibrations from the technical aspects of suppressing vehicle body vibrations and preventing noise.

That is, as for bending vibration, as shown in Fig. 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 C ₁ in which the peak of the amplitude appears at a predetermined frequency fo. The characteristics of
Moreover, it has been found that a one-node bending vibration Q ₁ appears as shown in the graph of FIG. 8, and a two-node bending vibration Q ₂ appears as shown in FIG.

The low-order bending vibrations of the one-joint bending and the two-joint bending excites the cylinder block, and are one of the major causes of noise generation in the passenger compartment as well as vibrations to the vehicle body.

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

<Problems to be solved by the invention> Therefore, in the conventional crank damper pulley structure shown in Fig. 6 above, the main focus is on the torsional damper function against torsional vibration, and the low-order bending mentioned above is A drawback was that it was difficult to adapt the dynamic damper function to vibrations.

That is, for example, in the technique shown in Japanese Utility Model Application Publication No. 5-14139, although a damper rubber is provided in the pulley hub, a damper mass is not provided, and therefore, there is no control for the low bending vibration. Since the damping function was not provided, the damping function was not fully exhibited.

Furthermore, in the damper pulley structure shown in Japanese Utility Model Application Publication No. 58-70554, the torsional damper function and the dynamic damper function against bending vibration are not differentiated, and sufficient dynamic damper performance cannot be exhibited. There was a difficult point.

Similarly, the device described in Japanese Patent Application Laid-Open No. 59-40060 placed emphasis on the torsional damper function, and had the problem that the dynamic damper function against bending vibrations was not fully utilized.

Furthermore, as shown in Japanese Utility Model Application Publication No. 59-141256, there is a technology that provides a mechanism to prevent radiated noise from the damper pulley, but it does not include a mechanism to suppress noise caused by bending vibration. As a result, I felt that the noise countermeasures were not sufficient.

The purpose of this invention was to solve the technical problem of vibration and noise of the crankshaft based on the above-mentioned conventional technology, and to provide a sufficient torsional damper function to the crankshaft to assist the engine in generating high horsepower and high torque. However, it does not hinder the weight reduction of crankshafts to improve fuel efficiency, and it also sufficiently damps and absorbs not only low-order torsional vibrations but also bending vibrations, and improves engine block performance. It is an object of the present invention to provide an excellent vehicle crank damper pulley structure that suppresses vibration noise and benefits the application field of noise countermeasure technology in the automobile industry.

<Means for solving the problem> In accordance with the above-mentioned purpose, the structure of this invention, which is summarized in the scope of the above-mentioned utility model registration claim, is to solve the above-mentioned problem. The crank damper pulley has a crank damper pulley structure in which the pulley hub, which is fixed via a set bolt, has a damper mass and damper rubber, and the damper rubber and damper mass of the Danamiku damper, which has a circular cross section, are layered along the axial direction in the vaginal part of the pulley hub. The crank damper pulley of the vehicle is integrally attached to the above-mentioned set bolt.

<Function> Thus, the damper rubber having a circular cross section and the pulley hub are cranked against the set bolt at the front vagina of the pulley hub which is fixed via the set bolt to the tip of the crankshaft attached to the internal combustion engine of a vehicle such as an automobile. It is a dynamic damper that is integrally fixed and layered by baking or other means along the axial direction of the shaft, and has no influence on the torsional damper installed on the outside of the pulley hub. By damping and absorbing natural vibrations, it is possible to prevent vehicle body vibration and noise caused by engine crankshaft rotation, and it is also easy to install and remove, making maintenance easier. This is a technical measure.

<Example> Next, an example of this invention will be described below based on FIGS. 1 to 5. Note that the same parts as those in the embodiment 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 and screwed into the front end of a crankshaft 1 installed in an internal combustion engine of an automobile (not shown) via a set bolt 2 via a keyway, as in the conventional manner.

On the outside of the pulley hub 3, a belt groove 4 is formed on the circumferential surface to form a torsional damper 7 for damping and absorbing torsional vibrations 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 integrally fixed.

As shown in FIG. 2, a disc-shaped damper support flange 8 is integrally formed near the engine of the set bolt 2 of the pulley hub 3, and the pulley hub 3 is attached to the flange 8. At the front, a damper rubber 9 with a circular cross section and a damper mass 10 with a ring-shaped cross section of a predetermined size are layered in the axial direction and fixed integrally by means such as baking to form a dynamic damper 11. It is equipped in A.

Note that the axial arrangement of the damper rubber 9 and the damper mass 10 may be reversed depending on the design.

In the above structure, as shown in FIG. 2, a damper mass 10 is baked onto the front surface of the flange 2 via a damper rubber 9 to a set bolt 2 integrally formed at the neck portion of the flange 8, thereby forming a dynamic damper 11. On the other hand, a damper mass 5 with a belt notch 4 formed thereon is integrally molded on the outer periphery of the pulley hub 3 via a damper rubber 6, and the pulley hub is attached to the tip of the crankshaft 1 via the set bolt 2 of the dynamic damper 11. 3 and secure them together.

Therefore, in this state, the dynamic damper 11 is naturally set in the vaginal part A of the pulley hub 3, as shown in FIG.

Of course, in this embodiment, the torsional damper 7 and the dynamic damper 11 are installed together, but for example, for a conventional engine crankshaft in which the dynamic damper 11 is not provided, It is only necessary to remove the set bolt that has already been attached, and then screw and fix the set bolt 2 to which the dynamic damper 11 is attached.

Therefore, the set bolt 2 of the dynamic damper 11 is different from the conventional dynamic damper 1.
The set bolt 2, which does not have the set bolt 1, has a common thread and is considered to be a compatible part.

When the crankshaft 1 rotates at high speed by driving the engine, torsional vibrations and the resulting noise are damped and absorbed by the torsional damper 7 in the same manner as in the conventional system.

As for low-order bending vibrations such as one-node bending vibrations and two-node bending vibrations, the dynamic damper 11 attached to the flange of the set bolt 2 in an axially stacked manner absorbs the vibrations and Dampens and absorbs noise.

Therefore, vibrations are not transmitted to the vehicle body, and noise is prevented from entering the vehicle interior.

In addition, as shown in FIG. 1, in this embodiment, which is equipped with a dynamic damper 11 consisting of a three-piece set bolt 2, flange 8, damper rubber 9, and damper mass 10, Torsional vibrations are damped and absorbed by the circumferential layering of the outer damper mass 5 and damper rubber 6, and the torsional damper function is fully demonstrated, but low-order bending vibrations such as one-node bending and two-node bending The vibration is suppressed and absorbed by the damper rubber 9 and the damper mass 10, which are layered in the axial direction, and the amplitude is suppressed as shown in graph C ₂ of Fig. 7, and the graph peak of C ₁ of the conventional mode is suppressed. is reduced,
Vibration reduction and noise suppression are fully demonstrated.

In this case, since the dynamic damper 11 is installed in the vaginal area A at the front of the pulley hub 3,
Space is also used effectively, and vibration damping and noise absorption for both torsional and bending vibrations are fully utilized.

Next, the embodiments shown in FIGS. 3 and 4 are the same in that the dynamic damper 11' for the crankshaft 1 mounted on a turbo engine is set in the vaginal part A at the front of the pulley hub 3. However, there is a pulley hub 3 at the tip of the crankshaft 1.
A female thread is threaded into the head of the set bolt 2' to be tightened and fixed, and a flange 8' as a disc-shaped support is integrally attached to the neck part of the sub-bolt 2'' as shown in Fig. 4. form,
A damper rubber 9' having a circular cross section and a damper mass 10' are integrally fixed to the flange 8' by baking to form a dynamic damper 11'. By screwing into the female thread of the head,
As shown in FIG. 3, the dynamic damper 11'
can be set in the pulley hub 3 and the vagina A. Therefore, for a pulley hub that does not have a conventional dynamic damper, the set bolt 2 can be removed and a set bolt 2' with a female thread cut into the head can be used. The dynamic damper 11' can be attached by screwing it on.

Therefore, in this embodiment, low-order bending vibrations such as one-node bending and two-node bending are sufficiently absorbed by the damper rubber 9' and the damper mass 10', which are layered in the axial direction, as in the previous embodiment, and furthermore, torsional vibrations are absorbed. It can also absorb vibrations and noise to the vehicle body.

Further, in the embodiment shown in FIG. 5, the set bolt 2'
A damper mass 10'' is baked and fixed directly to the head of the damper rubber 9' through the damper rubber 9', which is layered in the axial direction, and damps and absorbs large low-order bending vibrations such as those of the crankshaft of the turbo engine of the above two embodiments. This mode is more suitable for damping and absorbing the torsional vibration and cam bending vibration of the crankshaft of a non-turbo type engine.

Of course, in this embodiment as well, the set bolt of the pulley hub that does not have a conventional dynamic damper can be removed and the dynamic damper 1 of this embodiment can be installed.
A set bolt 2 integrally formed with a diameter of 1" is used.

It goes without saying that the embodiments of this invention are not limited to the above-mentioned embodiments. For example, the damper rubber of the dynamic damper 11 or the damper mass may be divided into a plurality of materials in the circumferential direction, or the damper support Various embodiments can be adopted, such as providing a damper rubber and a damper mass on the rear surface of the flange via another damper support.

<Effects of the invention> As described above, according to this invention, basically, in the pulley hub provided at the tip of the crankshaft provided in the internal combustion engine of a conventional automobile,
In addition to the conventional torsional damper on the periphery for torsional vibration, a dynamic damper has been integrated into the set bolt by utilizing the space in the front vagina of the pulley hub. It is an excellent product that can sufficiently damp and absorb low-order bending vibrations such as those caused by joint bending, and can therefore damp and absorb engine block vibrations and noise, ensuring quiet and quiet running. effective.

Further, this has the excellent effect of promoting weight reduction of not only the engine block but also the crankshaft, which can be useful for improving fuel efficiency, and also guaranteeing the strength of the crankshaft.

Furthermore, since the space in the front vagina of the pulley hub can be actively utilized, there is also the advantage that there is no need to expand the space occupied by the tip of the crankshaft in the engine room.

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

In addition, by utilizing the vagina in the front internal space of the pulley hub described above, maintenance such as inspection and maintenance can be easily performed without complicating the structure.

In this invention, the damper rubber and damper mass are attached to the flange, etc., which is integrally formed with the set bolt for attaching the pulley hub at the end of the crankshaft, so that the dynamic damper can be equipped simply by replacing the set bolt. This not only has the effect of improving workability and serviceability, but also allows a conventional dynamic damper or a dynamic damper with a common set bolt with the same male thread to be directly attached to the crankshaft. Excellent effects are produced.

[Brief explanation of the drawing]

Figures 1 to 5 are explanatory diagrams of embodiments of this invention. Figure 1 is a longitudinal sectional view of one embodiment, Figure 2 is a longitudinal sectional view of the same dynamic damper, and Figure 3 is another embodiment. FIG. 4 is a longitudinal sectional view of the same dynamic damper, FIG. 5 is a longitudinal sectional view of another embodiment, and FIG.
The figure is a longitudinal cross-sectional view of a torsional damper installed at the tip of a crankshaft in a conventional manner, Figure 7 is an amplitude graph of low-order bending vibrations versus frequency in the conventional manner and this invention, and Figures 8 and 9 are low-order bending vibrations. FIG. 3 is a schematic diagram of one-node bending vibration and two-node bending vibration. 1...Crankshaft, 2', 2'', 2...
Set bolt, 3... Pulley hub, 9... Damper mass, 10... Damper rubber.

Claims (1)

[Scope of utility model registration request] In a crank damper pulley structure in which a pulley hub is fixed to the tip of a crankshaft installed in a vehicle engine via a set bolt and has a damper mass and a damper rubber, a circular cross section along the axial direction inside the vagina of the pulley hub is used. A crank damper pulley structure for a vehicle, characterized in that the damper rubber and damper mass of the dynamic damper are layered and integrally attached to the set bolt.