JP2568591Y2 - Vibration and noise suppression device for fuel injection pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing vibration and noise of a fuel injection pump.

[0002]

2. Description of the Related Art Generally, a diesel engine is provided with a fuel injection pump (injection pump) for pumping fuel to be injected into a combustion chamber. This fuel injection pump is designed to pump the fuel at a high pressure, so that the driving torque is high, and the pressure becomes 0 at the moment when the injection is completed. This is repeated while the engine is running,
Vibration due to torque fluctuation is large and causes noise.

As a device for preventing such a vibration of the fuel injection pump, there has been proposed a "drive system for a fuel injection pump of an automobile" (Japanese Utility Model Laid-Open No. 56-94849). As shown in FIG. 4, in this proposal, a damper 3 is interposed between an injection pump gear 1 and a coupling 2. Injection pump gear 1
Is the idling gear 6 on the crank gear 5 of the engine 4
Are meshed through. The coupling 2 connects the timer 8 provided in the fuel injection pump 7 to the injection pump gear 1. With this configuration, vibration due to drive torque fluctuation is attenuated to prevent vibration and noise in the gear train.

[0004]

However, the configuration proposed above is insufficient for effectively reducing vibration and noise. That is, when the sound source analysis of the noise is performed, the noise from the coupling 2 is the largest in the drive system of the fuel injection pump 7. This is because the coupling 2 connects the drive shaft from the engine 4 side to the input shaft of the pump, and therefore has a structure that absorbs deviations such as eccentricity and declination of both shafts. This is because the rigidity is the weakest, and therefore the vibration is the largest.

In view of the above circumstances, the present invention has been devised to provide a vibration noise prevention device for a fuel injection pump that reduces vibration and noise particularly at the coupling.

Other techniques related to the present invention include a "slipping clutch with a self-excited torsional vibration absorbing damper" (Japanese Patent Laid-Open No. 62-46028) and a "damper" (Japanese Utility Model Laid-Open No. 55-126044). Gazettes), but none of them can be immediately applied to the above-described fuel injection pump.

[0007]

According to the present invention, a cylindrical portion that covers the outer periphery of a coupling is provided between a timer provided in a fuel injection pump and a coupling for connecting a pump drive shaft to the timer. And a cylindrical member provided with an annular mass that fits over a predetermined gap, and the gap is filled with a highly viscous fluid.

[0008]

With the above arrangement, the vibration transmitted from the fuel injection pump is attenuated by the shear resistance of the highly viscous fluid between the cylindrical portion of the disk and the mass body. In addition, the tubular portion blocks the sound radiated from the coupling.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of a vibration noise prevention device for a fuel injection pump according to the present invention. This apparatus has a circular plate having a cylindrical portion 15 that covers the outer periphery of a coupling 14 between a timer 12 provided in a fuel injection pump 11 and a coupling 14 for connecting a pump drive shaft 13 to the timer 12. The cylindrical portion 15 is provided with an annular mass body 17 fitted with a predetermined gap therebetween, and the gap is filled with a silicone oil 18 which is a highly viscous fluid. It is configured.

The fuel injection pump 11 is provided with a plunger (not shown) for pumping fuel to each cylinder of the engine and an injection pipe 19, and a known governor 20 is provided on the side opposite to the timer 12. . The timer 12 is attached to a cam shaft (input shaft) 21 of the fuel injection pump 11, and a weight (not shown) caused by rotation from the pump drive shaft 13.
Injection timing is adjusted by giving a phase difference in the rotation direction between the drive side and the pump side according to the amount of movement. The pump drive shaft 13 is appropriately connected to a crankshaft (not shown) of the engine, and transmits the rotational driving force to the coupling 14.

In the present embodiment, the cylindrical portion 15 is
Is formed by bending the outer peripheral edge of the coupling 14 in the axial direction, and its tip extends to the position of the end of the coupling 14 on the pump drive shaft 13 side.

The mass body 17 is formed of a metal such as iron, the axial length a of which is larger than the effective length b associated with the fitting of the cylindrical portion 15, and the outer diameter c is the outer diameter of the cylindrical portion 15. It is formed so as to be larger. Further, an annular fitting groove 22 cut from the end face on the shaft side is formed inside the mass body 17. The depth of the fitting groove 22 is formed slightly larger than the effective length b of the cylindrical portion 15, and the gap between the cylindrical portion 15 and the inner wall of the fitting groove 22 is filled with the silicon oil 18. Become. A seal (elastic member such as rubber) 23 for sealing the silicone oil 18 is fitted in the opening of the fitting groove 22.

Next, the operation of this embodiment will be described.

During operation of the engine, a rotational driving force is transmitted to the camshaft 21 of the fuel injection pump 11 to operate each plunger, thereby injecting fuel into the combustion chamber. With this pump operation, vibrations caused by torque fluctuations and the like are transmitted to the timer 12 and the coupling 14, but the vibrations are filled between the cylindrical portion 15 of the disk 16 and the mass body 17. Due to the viscous friction (shear resistance) of the silicon oil 18 that is present, it is quickly attenuated. The elasticity of the seal 23 also absorbs vibrations in the radial direction and the like and contributes to its attenuation.
The cylindrical portion 15 and the mass body 17 prevent noise caused by vibration transmitted to the coupling 14 from being radiated outward.

As described above, since the cylinder portion 15 and the mass body 17 which are engaged with each other via the silicone oil 18 are provided between the timer 12 and the coupling 14, the vibration of the fuel injection pump 11 having the largest vibration is provided. Vibration damping due to the viscosity of the silicon oil 18 is performed at the position on the rear end side, so that vibration due to torque fluctuation of the fuel injection pump 11 can be effectively suppressed, and the noise can be reduced. Further, since the cylindrical portion 15 and the mass body 17 are formed so as to surround the coupling 14, it is possible to suppress the sound radiated from the coupling 14.

Further, since the cylindrical portion 15 is extended in the axial direction, the engagement area between the mass body 17 and the cylindrical portion 15 can be increased, and the damping effect can be sufficiently exhibited. Further, by adopting this shape, even when a fuel injection pump having a different driving force is mounted, it is not necessary to largely change the layout (outer diameter c), but only by changing the axial length (a, b). It became possible.

FIG. 3 shows another embodiment of the present invention, in which a cylindrical portion 32 formed in a disk 31 is formed as a thick member in a radial direction, and a mass body 33 is accommodated therein. A fitting chamber 34 is formed. In a state where the mass body 33 is inserted into the fitting chamber 34, the surrounding gap is filled with the silicon oil 35, the vibration is attenuated by viscous resistance, and the cylindrical portion 32 is connected to the coupling 14.
The radiated sound is cut off by surrounding the outer periphery of. The other configurations, functions and effects are the same as those of the above-described embodiment.

In the above embodiment, silicon oil is used as the high-viscosity fluid, but any fluid may be used as long as it exerts an appropriate viscous friction force.

[0020]

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are exhibited.

A disk having a cylindrical portion that covers the outer periphery of the coupling is provided between the timer and the coupling. An annular mass is fitted into the cylindrical portion, and the gap is filled with a highly viscous fluid. Therefore, the vibration damping effect due to the viscous resistance of the fluid is effectively exerted, and the sound radiated from the coupling is cut off, thereby reducing the vibration and noise.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of a vibration noise prevention device for a fuel injection pump according to the present invention.

FIG. 2 is a view in the direction of arrow A in FIG. 1;

FIG. 3 is a side sectional view showing a main part of another embodiment of the present invention.

FIG. 4 is a side view showing a conventional vibration noise prevention device for a fuel injection pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Fuel injection pump 12 Timer 13 Pump drive shaft 14 Coupling 15 Tube part 16 Disk 17 Mass body 18 Silicon oil (high-viscosity fluid)

Continuation of the front page (56) References JP-A-62-46028 (JP, A) JP-A-57-117055 (JP, U) JP-A-56-94849 (JP, U) JP-A-51-226044 (JP, U) , U)

Claims (1)

(57) [Scope of request for utility model registration] A disk provided with a cylindrical portion for covering an outer periphery of the coupling between a timer provided in the fuel injection pump and a coupling for connecting a pump drive shaft to the timer; An apparatus for preventing vibration and noise of a fuel injection pump, comprising: an annular mass body fitted into a cylindrical portion with a predetermined gap therebetween; and the gap filled with a highly viscous fluid.