JPH063181Y2 - Anti-vibration structure of air cleaner device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a vibration isolation structure for an air cleaner device.

[Prior Art] There is a vehicle in which the main body case of the air cleaner is separated from the engine and attached to the body frame in the engine room, and the main body case and the intake manifold of the engine are connected by a rubber hose. It is fixedly supported on the vehicle body via the rubber mount of the.

[Problems to be Solved by the Invention] In such an air cleaner device, the main body case supported on the rubber mount constitutes a resonance system by its mass and the spring constant of the rubber mount. On the other hand, the intake air that circulates in the main body case and the rubber hose that make up the engine intake path pulsates with the periodic engine intake stroke, and pulsates at the resonance frequency determined by the capacity of the main body case and the diameter and length of the rubber hose. Indicates a maximum.

The intake pulsation acts as an exciting force on the main body case, and when the resonance frequency matches the resonance frequency of the main body case, it causes the main body case to vibrate greatly and causes a muffled sound.

As a countermeasure against this, it is necessary to change the specifications of the engine intake path to shift the above resonance frequency from the resonance frequency, and to provide an expansion chamber or a resonator for absorbing intake pulsation, or to provide a mass damper or a dynamic damper on the case body. Conceivable.

Of these, changes in specifications are naturally limited due to the conflict with other onboard equipment. On the other hand, it is desirable to install both resonators and dynamic dampers independently, so it is desirable to install both together, but in addition to securing sufficient space for installing these, it requires man-hours for each installation,
There was a problem that the number of parts also increased.

The present invention solves such a problem, and provides a vibration isolation structure for an air cleaner device that can realize a resonator and a dynamic damper in a relatively small space and does not increase the number of parts and the amount of work. To aim.

[Means for Solving Problems] The structure of the present invention will be described with reference to the drawings. The body case 2 of the air cleaner is fixed to the vehicle body B via an elastic mount.
In the air cleaner device in which the intake air after cleaning is supplied to the vehicle engine by the elastic hose 4 connecting the body case 2 and the intake manifold 3 of the vehicle engine, the elastic hose 4 is connected to the internal space 1a. A resonator 1 of a fixed volume is provided integrally with the elastic hose 4 through a passage, and the muffling frequency of the resonator 1 is set to the resonance frequency in the elastic hose 4 equal to the resonance frequency of the body case 2. The mass of the resonator 1 is made to match, and the mass of the resonator 1 is set so as to form a dynamic damper in which the natural frequency determined by the spring constant of the elastic hose 4 matches the resonance frequency of the main body case 2. I am doing it.

[Operation] During engine operation, intake pulsation occurs in the elastic hose along with the periodic intake stroke, and the pulsation rapidly increases at the resonance frequency. In this case, since the muffling frequency of the resonator is in the range of the resonance frequency, the increase of the pulsation is effectively suppressed.

On the other hand, the above pulsation vibrates the body case of the air cleaner,
Although this is made to resonate, the resonance vibration of the main body case can be suppressed to a small level by the dynamic damper formed by the resonator and the elastic hose.

[Effect] As described above, according to the vibration isolating structure of the present invention, the pulsation of the intake system that vibrates the main body case is suppressed by the resonator, and the vibration of the main body case due to the pulsation is also effective by the dynamic damper. This is combined with this effect, and the vehicle muffled noise caused by the vibration of the air cleaner body case is greatly reduced.

[Embodiment] In FIG. 1, an air cleaner main body of a known structure having a filter installed therein has a case 2 supported and fixed to a body frame B of a vehicle by a vibration-proof rubber mount 21.
Has a resonance frequency of

One end of a cool air duct 22 for introducing outside air is connected to the upstream opening of the main body case 2, and one end of a rubber hose 4 is connected to an outlet pipe 23 of the downstream opening. The other end of the rubber hose 4 is connected to the intake manifold 3 of the engine, and the rubber hose 4 is arranged in the hollow.
Has a spring constant of K1 and is bent and deformed in the vertical direction.

A rubber body layer 5 having a constant spring constant K2 is formed on an upper surface of an intermediate portion of the rubber hose 4, and a closed box-shaped resonator 1 having an internal space 1a having a constant volume is joined and fixed to the rubber body layer 5. There is. The mass of this resonator 1 is M.

The resonator 1 has an opening 11 of a predetermined size in a part of the bottom wall.
Is provided, and the opening 11 communicates with the inside of the rubber hose 4 by a communication passage 51 of a predetermined length provided in the rubber body layer 5.

The sound deadening frequency of the resonator 1 is determined by the volume of the internal space 1a and the cross-sectional area and length of the communication passage 51.
These are set so that the sound deadening frequency matches the resonance frequency in the rubber hose 4 which is equal to the resonance frequency fo.

The resonator 1, the rubber layer 5 and the rubber hose 4 constitute a dynamic damper having a natural frequency determined by its mass M and spring constants K1 and K2. The frequency is set to match the resonance frequency fo.

When the resonance frequency of the intake pulsation generated in the rubber hose 4 accompanying the intake stroke of the engine is in the vicinity of the resonance frequency fo, the pulsation vibrates the main body case 2 of the air cleaner.

Here, in the vibration isolating structure, the intake pulsation near the frequency fo is resonantly damped by the resonator 1, and the action of the vibration force on the main body case 2 becomes relatively small.
Further, even if the exciting force is applied, the vibration of the main body case 2 can be suppressed to an extremely small value by the anti-resonance action of the dynamic damper constituted by the resonator 1 and the rubber hose 4.

Thus, the vibration of the air cleaner body case is drastically reduced, and the muffled noise in the passenger compartment caused by the vibration is greatly reduced.

This effect is shown in FIG. In the figure, the line x indicates the present invention,
A line y shows a conventional example in which only a resonator is installed, and a line z shows an example in which no anti-vibration measure is applied. As can be seen from the figure, according to the present invention, the muffled sound level in the vehicle is greatly reduced in the vicinity of the engine speed No corresponding to the resonance frequency of the air cleaner body case.

In the above embodiment, the rubber body layer 5 and the rubber hose 4 can be integrally molded, which can reduce the number of mounting steps.

In the above embodiment, the rubber layer 5 is provided to adjust the natural frequency of the dynamic damper and is not always necessary.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional side view of an air cleaner device having a vibration isolation structure, and FIG. 2 is a diagram showing a muffled sound reducing effect. 1 ... Resonator 1a ... Internal space 2 ... Main body case 21 ... Rubber mount (elastic mount) 3 ... Intake manifold 4 ... Rubber hose (elastic body hose) 5 ... Rubber body layer (elastic body layer) 51 ... Communication passage B ... Vehicle body

Claims (2)

[Scope of utility model registration request] 1. A main body case of an air cleaner is fixed to a vehicle body via an elastic mount, and the intake air after cleaning is supplied to the vehicle engine by an elastic hose connecting the main body case and an intake manifold of the vehicle engine. In the air cleaner device, the elastic hose is integrally provided with a resonator having a constant volume, the internal space of which communicates with the elastic hose through a communication passage, and the silencing frequency of the resonator is set to the resonance vibration of the main body case. Equal to the resonance frequency in the elastic hose 4 and the natural frequency determined by the mass of the resonator and the spring constant of the elastic hose matches the resonance frequency of the main body case. Anti-vibration structure of the air cleaner device that is set to form a dynamic damper. 2. A dynamic layer having an elastic layer interposed between the resonator and the elastic hose, the dynamic frequency having the natural frequency depending on the combined spring constant of the elastic layer and the elastic hose and the mass of the resonator. An anti-vibration structure for an air cleaner device according to claim 1, wherein the utility model registration comprises a damper.