JPH026281Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a damper device for absorbing torsional vibrations applied to a crankshaft of an internal combustion engine.

For example, in multi-cylinder internal combustion engines such as trucks and buses, the crankshaft is long, has a low natural frequency during rotation, and is susceptible to torsional vibration. In order to effectively absorb the torsional vibrations of the crankshaft and prevent damage thereof, a damper device is provided along with the crank pulley at a portion that protrudes from the engine body.

This damper device includes a thin circular damper plate fitted onto a crankshaft, an elastic body made of a thick annular rubber material fixed along at least one peripheral edge of the damper plate, and an elastic body made of a thick circular rubber material. It consists of an inertial body made of a thick annular metal material that is fixed to one side of the body, which is the side opposite to the damper plate, and the inner and outer circumferential surfaces of the elastic body that are in contact with the inertial body or the damper plate, Stress tends to concentrate more easily than in the radial center of the elastic body.
There was a risk of cracks occurring.

Therefore, in order to alleviate this stress concentration, a wrap-around part formed integrally with the elastic body is provided on the entire inner and outer circumferential surfaces of the inertial body. −145850.

However, the above-mentioned elastic body is used to bond the damper plate and the inertial body together by hot-pressure bonding, and for example, when the inertial body is attached to the lower die that constitutes the mold, and the damper plate is attached to the upper die, the two dies are put together. The rubber material is fluidly filled into the space formed between the two molds from a sprue provided in the upper mold via a damper plate.

When attaching the inertial body to the lower mold so that wrap-around parts integral with the elastic body are formed on the inner and outer circumferential surfaces of the inertial body, there are no suitable positioning parts other than the inner and outer circumferential surfaces of the inertial body, and the inertial body Even if holes or protrusions are provided in the side surface and the lower die for positioning, the cost will increase, and the coaxiality with the crankshaft will deteriorate, making it impossible to maintain static balance. Furthermore, when the engine rotates at high speed, the inertial body places a heavy burden on the elastic body, which may cause the rubber to peel or crack.

The present invention was developed in view of the above circumstances, and its purpose is to provide a damper device that can improve durability and suppress operational noise without impairing the effects of the elastic body and inertial body. This is what I am trying to do.

Hereinafter, one embodiment of the present invention will be described based on the drawings. FIG. 1 shows a part of the damper device, and 1 is a damper plate made of a thin circular metal plate.A fitting hole 2 for fitting the crankshaft S is provided in the axial center of the damper plate. Attachment holes 3 are provided at predetermined intervals along the circumferential surface. These mounting holes 3 are used when mounting the damper plate 1 with mounting bolts to the side surface of a crank pulley (not shown) that fits into the crankshaft S. Further, the damper plate 1 has a slightly tapered outer peripheral edge, and thick annular first and second elastic bodies 4a and 4b made of a rubber material are spaced apart from each other at a predetermined interval on the peripheral edge of the side surface. It is flow glued. That is, the first elastic body 4a is located on the axial center side of the tapered surface of the damper plate 1, and the second elastic body 4a
b are adhered to the peripheral end sides, respectively. Further, a thick annular first inertial body 5a made of a metal material is provided on the other end surface side of the first elastic body 4a, which is the side opposite to the damper plate 1, and the second elastic body 4b is similarly provided with a thick annular first inertial body 5a. The second inertia bodies 5b are each hot-glued.
The entire inner circumferential surface 15a of the first inertial body 5a and the middle part of the outer circumferential surface 25a are covered by a first thin wall of about 0.5 m/m, which is an extension of a part of the first elastic body 4a. It is covered with the wrap-around portion 14a and the second wrap-around portion 24a. Therefore, the second wrapping portion 24a is formed on the outer peripheral surface 25a of the first inertial body 5a.
It is formed short in the axial direction of the crankshaft S so that a part of it is exposed. That is, the second wrapping portion 24a of the first inertial body 5a
A portion of the exposed outer circumferential surface 25a that is not covered by the outer circumferential surface 25a forms an annular positioning portion to be described later, and for convenience of explanation, this positioning portion is designated by the same reference numeral 25a. Outer peripheral surface 25b of the second inertial body 5b
is approximately the length of the second elastic body 4b extended.
It is covered with a third wrapping portion 24b having a thin wall of about 0.5 m/m.

The damper device configured in this way has a second
It is manufactured as shown in the figure. That is, 7 is an upper mold, 8 is a lower mold, and these constitute a mold 9. The upper mold 7 is equipped with sprues 10, 10, and the tapered surface of the damper plate 1 is mounted thereon. The gates 10, 10 communicate with guide holes 11, 11 formed in the tapered surface of the damper plate 1. The lower mold 8 has a recess 12 on its outer circumferential side, into which the second inertial body 5b is attached, and a flange 1 on its inner circumferential side.
It has 3. The tip edge of the flange portion 13 contacts the tapered surface of the damper plate 1, and the outer circumferential surface 13b has a narrow space of about 0.5 m/m between the outer circumferential surface 13b and the opposing circumferential surface of the second inertial body 5b. It is formed so that it exists. The outer circumferential surface 13a has its proximal end fitted into an annular positioning portion 25a formed on a part of the outer circumferential surface of the first inertial body 5a, and forms a positioning portion for the first inertial body 5a. portion is approx.
There is a gap of about 0.5m/m. Note that when the upper mold 7 and the lower mold 8 are combined in this way, there is a space 3 partitioned by a flange portion 13 between them.
Of course, 5a and 35b are formed.

Thus, by injecting rubber under pressure from each sprue 10, 10, each space 35a, 35b is filled.
At this time, since the positioning portion 25a formed on a part of the outer circumferential surface of the first inertial body 5a is directly fitted to the inner circumferential surface of the flange portion 13, the position of the first inertial body 5a does not shift in the radial direction. . That is, the accuracy of the coaxiality of the first inertial body 5a with respect to the damper plate 1 is extremely high, and the rubber evenly wraps around the inner circumferential surface 15a and the outer circumferential surface other than the positioning portion 25a, so that they have the same thickness. . Similarly, the second inertial body 5b is positioned by the recess 12 of the lower die 8, so its coaxiality with the damper plate 1 is extremely high, and the rubber wraps around between its inner peripheral surface 25b and the flange 13. Obtain uniform wall thickness. In the end, the first
First to third wrap-around portions 14 as shown in the figure
A double mass type damper device having a, 24a, and 24b is constructed.

Thus, the damper device absorbs torsional vibrations caused by the rotation of the crankshaft S. Since the coaxiality of each inertial body 5a, 5b is extremely high, the static balance with respect to the damper plate 1 is good, and even when rotating at high speed, the load on each elastic body 4a, 4b is small, and these cracks and peeling are avoided. do not have.

In this way, in the above embodiment, the first to third wrap-around parts 14a, 24a, 24b are provided, and each inertial body 5a, 5b is connected to the elastic body 4a, 24b.
Since all the corners joining with the elastic bodies 4b are rounded, there is no stress concentration on the corners of the elastic bodies 4a and 4b.

Note that in the above embodiment, the first inertial body 5
Although the annular positioning part 25a formed on the outer peripheral surface of the elastic body 4a is covered with the second wrapping part 24a of the elastic body 4a, the present invention is not limited to this. For example, as shown in FIG. 1 inertial body 5
An annular positioning portion 15a' may be left on the inner peripheral surface of a' and covered with the elastic body 4a'. That is, the flange portion of the mold (not shown) is placed in the positioning portion 15.
a' to perform hot-flow adhesion, and the coaxiality of the inertial body 5a' can be achieved with extremely high accuracy. At this time, the outer peripheral edge of the damper plate 1' is bent in the opposite direction to the tapered surface, and the outer peripheral surface 24a' of the first elastic body 4a' is bent at the bent portion 1.
a and slightly protrudes from the outer circumferential surface 25a' of the first inertial body 5a'. The second elastic body 4b' and the second inertial body 5b' are hot-adhered to the outer peripheral surface of the bent portion 1a via a metal sleeve 16. The sleeve 16 can protect the elastic body 4b' when it is press-fitted into the bent portion 1a.

FIG. 4 shows that the first inertial body 5a'' has a stepped annular positioning part 25a'' on the outer circumferential surface, and this is fitted into a flange part of a mold (not shown) to form the first elastic body 4.
a''. At this time as well, the inertial body 5
a'' coaxiality can be achieved with extremely high precision.The first and second elastic bodies 4a'' and 4b'' may be hot-glued on both sides of the damper plate'', and the second
The inertial body 4b'' has an inverted L shape for balance.

Of course, with either structure, the same effects as those of the above embodiments can be obtained.

Furthermore, although each of the above embodiments has been described with reference to a so-called double mass type having two inertial bodies, the present invention is not limited to this, and can be applied even when the inertial body is a single body.

As explained above, according to the present invention, a wrap-around portion is provided that extends integrally from the elastic body to the inner and outer circumferential surfaces of the inertial body, and at least one of the inner and outer circumferential surfaces of the wrap-around portion is exposed. The damper plate of the inertial body was formed short in the axial direction of the crankshaft to provide an annular positioning part, and the damper plate of the inertial body was configured to position the inertial body when hot-flow bonding the inertial body to the damper plate. It is possible to significantly improve the coaxiality with respect to the axial direction, and it is easy to maintain static balance. Therefore, with a very simple configuration, the load on the elastic body due to inertial force during high-speed rotation can be reduced to prevent peeling, thereby improving durability and reducing operating noise.

[Brief explanation of the drawing]

Fig. 1 is a partial longitudinal sectional view of a damper device showing one embodiment of the present invention, Fig. 2 is a diagram of its manufacturing state, and Figs. 3 and 4 are damper devices showing other embodiments of the present invention, respectively. FIG. S... Crankshaft, 1... Damper plate, 5a, 5b... (first, second) inertia body, 4
a, 4b...(first, second) elastic body, 15a,
25a... (inertial body) inner peripheral surface, outer peripheral surface, 14a
...first wrap-around part, 24a...second wrap-around part.

Claims (1)

[Scope of utility model registration request] A damper plate that is attached to a crankshaft, and an annular inertia body that is provided with an elastic body interposed in the side periphery of the damper plate, in which the inertia body is attached to the elastic body. An annular shape in which a wrap-around portion is provided that extends integrally along the inner and outer peripheral surfaces of the body, and at least one of the inner and outer circumferential surfaces of the wrap-around portion is formed short in the axial direction of the crankshaft so that a part of the circumferential surface is exposed. A damper device comprising a positioning section.