JPS5927562Y2 - torsional damper - Google Patents

Description

[Detailed description of the invention] The present invention relates to a torsional damper for preventing torsional vibration that is attached to the end of a rotating shaft such as a crankshaft of an internal combustion engine.
In particular, the present invention relates to a disc-type torsional damper that suppresses vibration noise generated due to bending vibration of a rotating shaft.

In the crankshaft of an internal combustion engine, when the crankshaft is subjected to sudden changes in impact velocity due to an explosion, it receives torsional force, which generates torsional vibrations in the crankshaft, causing noise and wear in the engine, and eventually causing the crankshaft to break. reach.

As a countermeasure to this problem, conventional methods have been used to suppress torsional vibration.
A torsional damper is attached to the tip of the crankshaft.

FIG. 1 shows an example of a disc type torsion damper, in which an annular flat plate member 3 is fastened to a pulley 2 fitted and fixed to the tip of a crankshaft 1, and the peripheral side wall of the plate member 3 is a rubber member. 4. It is formed by sequentially polymerizing and adhering the inertia weight members 5.

However, in such a conventional simple disk-shaped torsional damper, the peripheral portion of the plate member 30 is shaped to be easily deflected to both sides in one direction of the crankshaft. Also, vibration occurs in the crankshaft direction with nodes in the circumferential direction.

There is also a cylindrical torsional damper in which an elastic material is interposed inside the pulley, and although this vibration does not pose a problem, it is difficult to manufacture and expensive.

The present invention was devised in view of these conventional drawbacks, and provides a torsional damper having a truncated cone shape with an inclined peripheral portion.

FIG. 3 shows a basic embodiment of the invention.

In the figure, a pulley 2 is pivotally connected to a crankshaft 1 and rotates together with the crankshaft 1, and a torsional damper T according to the present invention is attached to the pulley 2.

That is, in the torsional damper T, a metal play 1 material 11 serving as a substrate is formed in the shape of a truncated cone, and a hole 11a opened in the center fits into the boss portion of the pulley 2.
The flat portion 11A on the outer periphery is bolted to the pulley 2 and fixed.

As shown in the figure, a metal inertia weight member 13 is overlaid and adhesively fixed to the outer surface of the peripheral wall portion 11B of the plate member 11, which is inclined with respect to the crankshaft 1, via a rubber member 12.

With such a structure, the peripheral side wall 11B of the plate member 110 formed in a truncated cone shape, the rubber member 12 overlapping the peripheral side wall 11B, and the inertia weight member 13 are bent in the mode shown in FIG. Since the damper has a difficult shape, the axial vibration of the torsional damper shown in FIG. 2 and the noise accompanying the vibration can be effectively suppressed.

FIG. 4 shows an application example of the present invention, in which an inertia weight member 23 is polymerized and bonded via a rubber member 22 to the outer surface of the peripheral side wall of a metal plate member 210 formed into a truncated cone shape as in the previous embodiment. The inertial weight member 23 is made of a viscoelastic material 23.
A is formed of so-called divided plywood sandwiched between a pair of metal restraining plates 23B and 23C.

Further, a sound absorbing material 24 is adhesively fixed to the peripheral wall surface of the plate member 21 on the side opposite to the side to which the rubber member 22 is bonded.

With this structure, in addition to the vibration damping function of the crankshaft direction vibration due to the torsional damper having a truncated conical shape as in the previous embodiment, vibration in the same direction is also suppressed by the inertia weight member 23 made of vibration damping plywood. be done.

That is, the pair of metal restraint plates 23B and 23C of the inertial weight member 23 tend to shift in parallel due to vibrations in the crankshaft direction, but the viscoelastic member 23A regulates this shift, which absorbs energy and performs a vibration damping function. This results in the following.

Furthermore, modes as shown in FIG. 2 can also be allocated.

Furthermore, the sound absorbing material 24 absorbs the noise generated from the engine front cover and prevents it from resonating within the bowl shape, thereby further enhancing the vibration noise prevention effect.

Incidentally, in the torsional damper having this example structure, the inclination angle α of the peripheral part with respect to the central part mounting surface is 45°.
and 30' vibration and noise level of the
FIG. 5 shows experimental values compared with the conventional structure shown in the figure.

As is clear from the figure, the vibration and noise level of the device of the present invention is significantly reduced compared to the conventional device in the entire rotational speed range of the crankshaft, and the one with an inclination angle α of 45° is 30
The noise level is lower than that of the truncated conical shape, which shows the effectiveness of the truncated conical shape.

As explained above, in the present invention, the circumferential side wall of the disk-type torsional damper is formed into a truncated cone shape that is inclined with respect to the damper mounting surface perpendicular to the rotation axis. It has a structure that is difficult to bend, and can thereby extremely effectively suppress noise generated by vibrations in the coaxial direction.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a conventional torsional damper structure.
Figures 2A-F are diagrams showing vibration modes generated in a torsional damper with the same structure, Figure 3 is a sectional view showing a basic embodiment of the invention, and Figure 4 is an example of application of the invention. The cross-sectional view, FIG. 5, is a graph comparing the noise level generated by the torsional damper shown in the embodiment of FIG. 4 and a conventional torsional damper. 1...Crankshaft, 2...Pulley, 1
1, 21...Plate member, 11B...
・Peripheral wall part, 12゜22...Rubber part, 13
, 23...Inertia weight member.

Claims (3)

[Scope of utility model registration request] (1) In a disc-shaped torsional damper in which an inertia weight member is polymerized and bonded to a disc-shaped plate member via an elastic material, the central part of the truncated conical plate member is pivotally connected to the rotating shaft. , the angle α between the center mounting surface of the plate member and the generatrix of the cone is 25°≦α≦60°, the shape of the inertia weight member is conical, and the peripheral side wall is provided with an elastic material. Polymerizing and bonding the inertia weight member,
A torsional damper characterized by being integrated. (2) Utility model registration claim 1 in which the inertia weight member is formed in a multilayer structure in which a viscoelastic material is sandwiched between restraining plates.
Torsional damper as described in section. (3) The torsional damper according to claim 1 or 2, wherein the plate member has a sound absorbing material bonded to the surface opposite to the side to which the elastic material is bonded.