JPS6336191Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a double mass damper device that absorbs torsional vibrations applied to the crankshaft of an internal combustion engine by deforming two rubber members.

The crankshaft of an internal combustion engine generates torsional vibrations about the center line of rotation when it rotates. In particular, when the resonance frequency at which the torsional vibration of the crankshaft peaks and the rotational speed of the crankshaft are in harmony, resonance accompanied by large torsional deformation is likely to occur. As a damper device for reducing or dispersing the peak of such torsional deformation, there is a known damper device that converts torsional vibration energy into deformation of an elastic body such as rubber, which is then converted into thermal energy and dissipated. .

By the way, the torsion amplitude ratio of the crankshaft shows a peak value when the crankshaft resonates,
When a conventional single mass damper device is attached to this, the peak is divided into two as shown by the broken line in FIG. 1, and its value is reduced. In order to further reduce this peak value, a double-sided double-mass type damper device A as shown in Fig. 2 or a single-sided double-mass type damper device B with a rubber member provided concentrically on one side as shown in Fig. 3 are available. is considered valid. In this case, there is an advantage that the torsional amplitude of the crankshaft is reduced to approximately half that of a single mass, as shown by the solid line in FIG.

In other words, the conventional single mass damper with one degree of freedom can change the torsional vibration characteristics of the crankshaft and control the torsional vibration response of the shaft system by selecting the mass and spring of the damper. Expanding on this concept, a double mass damper with two degrees of freedom and two sets of masses and springs arranged in parallel can further control the torsional vibration response to suit the purpose. Figure 4 shows a vibration model in which the crankshaft system is replaced with an equivalent vibration system with three degrees of freedom when a torsional vibration damper is installed.

I: Moment of inertia C: Damping coefficient K: Complex spring constant of damper rubber η: Loss coefficient of damper rubber shows.

The equation of motion for this vibrating system is as follows.

IeX¨e+CeX〓e+KeXe +K ₁ ( _Xe −X ₁ )+K ₂ ( _{Xe − X 2} )=F …(1) I _{1 2} +K ₂ (X ₂ −Xe) ^{= 0 … (} 3) Here, if the excitation force F and the response amplitude (i=e, 1, 2: Subscripts are as shown in Figure 4.)
...(5) Furthermore, assuming that other symbols are as shown in Figure 4, equations (1), (2), and (3) become as follows.

(1−λ ² +j・2ζλ)θe+μ ₁ λ ₁ ² (1+jη)(θe
−
θ ¹ ) +μ ₂ λ ₂ ² (1+jη) (θe−θ ₂ )=1 …(6) λ ₁ ² (1+jη) (θ ₁ −θe)−λ ² θ ₁ =0…(7) λ ₂ ² ( 1+jη)(θ ₂ −θe)−λ ² θ ₂ =0…(8) However, the parameter using the above equation is the moment of inertia ratio: μi=Ii/Ie(i=1,2)…(9) The damper rubber Complex spring constant: Ki = Ki (1 + jη), (i = 1, 2) ... (10) Natural frequency: i = √ () / 2π (i = 1, 2) ... (11) Natural frequency ratio: λi = i / fe, (i = 1, 2) ... (12) Damping coefficient ratio: ζ = Ce / (2√) ... (13) Static angular displacement: x _p = Fo / Ke ... (14) Excitation frequency Ratio: λ = /e ... (15) Response amplitude ratio: θi = x _i /x _p (i = e, 1, 2) ... (16) As shown in Figure 1, the total moment of inertia of the damper and the damper rubber Assuming that the loss coefficient is constant,
When the vibration characteristics of the damper are selected so that the heights of the resonance peaks of the vibration system are the same, the double mass damper (solid line) has a crankshaft torsional resonance peak height of 50% compared to the single mass damper (dashed line).
% can be reduced.

However, when the three resonance peaks and nodes of the crankshaft are within the engine's normal rotation range, there is a problem in that noise is generated due to torsional vibration of the crankshaft.

This idea was devised by focusing on the above-mentioned circumstances, and its purpose was to eliminate the resonance peak of the crankshaft, which has a high frequency and is difficult to maintain in terms of durability.
The object of the present invention is to provide a double mass damper device in which the heights of the nodes are made the same and the noise generated by the torsional vibration of the crankshaft can be reduced over the entire rotation range.

This invention will be explained below based on embodiments shown in the drawings. FIG. 5 shows a first embodiment, where 1 is a crankshaft. At the end of this crankshaft 1 is a crankshaft pulley 2.
is attached by a nut 4 using a taper cone 3. A double mass damper device 5 is fixed to the crankshaft pulley 2 with bolts 6. The damper plate 7 of this double mass damper device 5 has a disk shape, and has an opening 8 in the center that fits into the crankshaft 1, and the bolt 6 on the periphery of the opening 8.
A plurality of through holes 9 are drilled through which the holes are inserted.
Further, a first annular inertia body 11 is adhered to one side of the outer peripheral edge of the damper plate 7 via a first annular rubber member 10, thereby forming a first damper 12. Further, a second annular body 14 is provided on the other side of the outer peripheral edge of the damper plate 7 via a second annular rubber member 13.
are adhered to form the second damper 15.

The double mass damper device 5 rotates together with the crankshaft 1, and absorbs the torsional vibrations applied to the crankshaft 1 from the first and second rubber members 1.
It is designed to be absorbed by deformation of 0.13. The moment of inertia ratio and natural frequency ratio of the double mass damper device 5 are formed as follows. That is, Id ₁ : Moment of inertia of the first damper Id ₂ : Moment of inertia of the second damper I _E : Equivalent moment of inertia of the crankshaft d ₁ : Natural frequency of the first damper d ₂ : Moment of inertia of the second damper Natural frequency _E : Equivalent natural frequency of crankshaft η: Rubber loss factor Moment of inertia ratio 0.25≦Id ₁ /I _E /0.35 0.1≦Id ₂ /I _E ≦0.2 Natural frequency ratio 0.65 ＜ _d1 ／ _E ≦0.72 1.04≦ _d2 ／
_E <1.1 0.15≦η≦0.3.

When the above equation is graphed, as shown in FIGS. 6 and 7, the moments of inertia Id 1 and Id ₂ of the first and second dampers 12 and ₁₅ are 0.25 with respect to the equivalent moment of inertia I _E of the crankshaft 1. ~0.35 and 0.1~
It is formed to fall within the range of 0.2. Then, as shown in FIG. 8, the first and second dampers 1
The natural frequency ratios d ₁ and d ₂ of 2 and 15 are set to satisfy 0.65 to 0.72 and 1.04 to 1.1.

Under these conditions, the crankshaft 1 and the first and second dampers 12, 15 are matched with each other, and as shown in FIG.
The amplitude peaks of the first rubber member 10 and the second rubber member 13 can be harmonized. In other words, the relative torsional amplitude of the rubber part at the knots where the frequency is high and durability is critical can be reduced. (~
When nodal vibration enters normal rotation), the tip torsion amplitude ratio of the crankshaft 1 makes the heights of the nodes the same.

FIG. 10 shows a second embodiment of this invention, in which a first rubber member 17 and a second rubber member 18 are disposed concentrically on one side of a damper plate 16. The inertial bodies 19 and 20 are glued together, and the first
Second dampers 21 and 22 are formed therein.
Double mass damper device 23 configured in this way
Similarly to the first embodiment, similar effects can be obtained by setting the conditions of the moment of inertia ratio and the natural frequency ratio.

As explained above, according to this invention, the heights of the resonance peaks of the crankshaft can be made equal by setting the inertia moment ratio, natural frequency ratio, and rubber loss coefficient of the first and second dampers. This has the effect of reducing the noise generated by the torsional vibration of the crankshaft over the entire rotation range.

[Brief explanation of the drawing]

Figure 1 is a characteristic diagram of the vibration mode of the damper device.
Figure 2 is a partial cross-sectional view of a double-sided double mass damper device, Figure 3 is a partial cross-sectional view of a single-sided double mass damper device, Figure 4 is an explanatory diagram showing an equivalent vibration model with three degrees of freedom, and Figure 5 is a partial cross-sectional view of the double-sided double mass damper device. FIGS. 6 and 7 are partial cross-sectional views of a double mass damper device showing a first embodiment of the present invention, and FIGS. 8 is a graph showing the relationship between the natural frequency of the crankshaft and the natural frequency of the first and second dampers, and FIG. 9 is a graph showing the relationship between the natural frequency of the crankshaft and the natural frequency of the first and second dampers. FIG. 10 is a partial sectional view of a single-sided double mass damper device showing a second embodiment of this invention. 1... Crankshaft, 7, 16... Damper plate, 10, 17... First rubber member, 1
1, 19...first inertial body, 12,21...first
damper, 13, 18... second rubber member, 1
4, 20... second inertial body, 15, 22... second
damper.

Claims (1)

[Claims for Utility Model Registration] First and second inertial bodies are attached to a damper plate attached to a crankshaft via first and second rubber members having different spring constants, and In a double mass damper device configured with two dampers, Id ₁ : Moment of inertia of the first damper Id ₂ : Moment of inertia of the second damper I _E : Equivalent moment of inertia of the crankshaft d ₁ : Inherent moment of the first damper Frequency d ₂ : Natural frequency of the second damper _E : Equivalent natural frequency of the crankshaft η : Loss factor of the rubber Moment of inertia ratio 0.25≦Id ₁ /I _E ≦0.35 0.1≦
Id ₂ /I _E ≦0.2 Natural frequency ratio 0.65＜d ₁ / _E ≦0.72 1.04≦d ₂ / _E
<1.1 A double mass damper device characterized by satisfying 0.15≦η≦0.3.