JP2014084782A - Resonator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drain water through a drain hole without varying noise reduction characteristics.SOLUTION: A resonator 10 includes: a drain hole 20 formed vertically penetrating a bottom part of a resonance chamber 12; and an opening/closing member 30 which is swingably supported on the resonance chamber 12 through a shaft part to swing, and displaced between a closing attitude for closing the drain hole 20 and an opening attitude for opening the drain hole. The opening/closing member 30 has one swing end part formed to be heavier than the other swing end part and is held in the closing attitude with the weight the one swing end part, and the other swing end part has a water reservoir recessed part formed to receive water flowing down from the resonance chamber 12 and to reserve the water by such an amount that the other swing end part becomes heavier than the one swing end part.

Description

  The present invention relates to a resonator provided in an intake system of an internal combustion engine.

  In an internal combustion engine mounted on a vehicle such as an automobile, a resonator is disposed in the middle of the intake duct in order to reduce intake noise generated when air is sucked through the intake duct. The resonator is a hollow box-like body, and reduces intake noise and the like using a resonance action by a resonance space defined inside the box-like body. In the resonator, water mixed with the air taken in from the outside by the intake duct or water generated by condensation accumulates in the resonance space, so a drain hole is formed at the bottom of the box-shaped body, and the water is removed through this drain hole. Configured to drain.

JP 2000-27719 A

  In the resonator, the volume of the resonance space is set according to the frequency of noise to be reduced. However, since the sound reduction characteristic is reduced by forming the water drain hole, it is necessary to increase the volume of the resonance space in order to ensure the equivalent sound reduction characteristic, leading to an increase in the size of the resonator. There are difficulties. In addition, the resonator in which the water drain hole is formed shifts to a higher frequency band where the sound can be reduced, and this frequency band shift is very difficult to obtain by simple analysis. For this reason, in the manufactured resonator, it takes time and effort to adjust the frequency aiming at sound reduction by adjusting the position, number and size of the drain holes, and the cost of correcting the mold of the resonator cannot be ignored.

  That is, the present invention has been proposed in order to suitably solve these problems inherent in the resonator according to the prior art, and the water drain hole does not change the sound reduction characteristics. An object of the present invention is to provide a resonator that can be drained through a wall.

In order to overcome the above-mentioned problems and achieve the intended object, the resonator according to the first aspect of the present invention provides:
A drain hole formed in the bottom of the resonance chamber in a vertical direction;
An opening / closing member that is pivotally supported with respect to the resonance chamber via a shaft portion and that is displaced between a closed posture that closes the drain hole and an open posture that opens the drain hole;
The opening / closing member is formed such that one oscillating end is heavier than the other oscillating end sandwiching the shaft portion, and is held in the closed posture by the weight of the one oscillating end, A water storage recess is formed in the oscillating end portion of the oscillating end portion for receiving water flowing down from the resonance chamber and storing an amount of water in which the other oscillating end portion is heavier than the one oscillating end portion, The gist of the invention is that the water is stored in the water storage recess and is displaced to the open posture and drains from the water storage recess.
According to the first aspect of the invention, since the drain hole is closed by the opening / closing member, the sound reduction characteristic is not changed by forming the drain hole. Further, when water accumulates in the resonance chamber, the opening / closing member is displaced so as to open the drain hole, so that the water accumulated in the resonance chamber can be discharged through the drain hole.

The gist of the invention according to claim 2 is that a restricting portion is provided at an opening edge of the drain hole to restrict one swinging end portion of the opening / closing member from being displaced downward from the closed posture. To do.
According to the invention which concerns on Claim 2, an opening-and-closing member can be hold | maintained in a closed attitude | position by a control part.

  According to the resonator according to the present invention, the water can be drained through the drain hole without changing the sound reduction characteristic by the drain hole.

1 is a front view showing a resonator according to a preferred embodiment of the present invention with a part broken away. It is explanatory drawing which shows the principal part of the resonator of an Example, (a) shows the case where an opening-and-closing member exists in a closed attitude | position, (b) shows the case where an opening-and-closing member exists in an open attitude | position. It is a top view which shows the opening-and-closing member of an Example. FIG. 4 is a sectional view taken along line AA in FIG. 3. It is a schematic perspective view which shows the opening-and-closing member of an Example, (a) shows the state isolate | separated from the drain hole, (b) shows the state attached to the drain hole.

  Next, a preferred embodiment of the resonator according to the present invention will be described below with reference to the accompanying drawings. In addition, the direction of a resonator is designated on the basis of the installation attitude | position which connected the resonator to connection objects, such as an intake duct.

  As shown in FIG. 1, a resonator 10 according to an embodiment includes a resonance chamber 12 that defines a hollow resonance space 12a therein, and a cylinder that is provided in the upper portion of the resonance chamber 12 and that has a passage connected to the resonance space 12a. And an upper end portion of the connection portion 14 is connected to a connection target (not shown) such as an intake duct. The resonator 10 according to the embodiment has an opening of a box-like lower half 16 that opens above the resonance chamber 12 and a box-like upper half 18 that opens below the resonance chamber 12. The flange portions 16a and 18b extending at the edges are brought into contact with each other and assembled by engagement or adhesion with claws. The lower half 16 and the upper half 18 can be formed by molding a synthetic resin such as injection molding. In the resonator 10, a drain hole 20 is vertically formed in the bottom of the resonance chamber 12, and an opening / closing member 30 that can open and close the drain hole 20 is disposed in the bottom of the resonance chamber 12. The bottom of the resonance chamber 12 in which the water drain hole 20 is formed is a lowermost part of the resonance chamber 12, and water that has entered the resonance chamber 12 is collected in the water drain hole 20. The resonance chamber 12 is formed with a round bar-shaped shaft portion 22 (see FIGS. 3 and 5) so as to span between the opening edges of the rectangular drain hole 20 facing each other. Here, the shaft portion 22 extends in the short direction between the opening edges on the long side of the drain hole 20.

  The opening / closing member 30 is pivotally supported with respect to the resonance chamber 12 via the shaft portion 22, and has a closed posture (see FIG. 2A) for closing the drain hole 20, and a drain hole 20. It is configured to be displaced between an open posture (see FIG. 2B) that opens. The opening / closing member 30 is a plate-like member made of synthetic resin or the like, and is formed in a rectangular outer shape in plan view in accordance with the opening shape of the drain hole 20 (see FIG. 3). The opening / closing member 30 is provided with a bearing portion 32 having a shaft groove 32a extending in the short direction of the opening / closing member 30 and opening downward (see FIG. 5). ). In the bearing portion 32, the closed end of the shaft groove 32 a is formed to match the shaft portion 22, while the open end of the shaft groove 32 a is formed slightly smaller than the diameter of the shaft portion 22, The groove 32a is removable. The opening / closing member 30 is assembled to the resonance chamber 12 by fitting the shaft groove 32 a of the bearing portion 32 to the shaft portion 22 from above (inside the resonance chamber 12). The opening / closing member 30 of the embodiment extends horizontally so as to be aligned with the bottom of the resonance chamber 12 in the closed posture, and is inclined so as to be inclined obliquely so as to intersect the bottom of the resonance chamber 12 in the open posture. It is configured to swing around 22 as a fulcrum. Note that the shaft portion 22 or the bearing portion 32 may be configured such that the posture of the opening / closing member 30 can be smoothly changed by coating a material having a small friction coefficient such as a fluororesin.

  The opening / closing member 30 is formed such that one oscillating end (referred to as a weight side end) 34 is heavier than the other oscillating end (referred to as a water storage side end) 36 sandwiching the shaft portion 22. The end portion 34 is held in a closed posture by the weight. The opening / closing member 30 sets a swing fulcrum so that the weight side end 34 is longer than the water storage side end 36, sets the weight side end 34 to be thick, or arranges a weight separately. For example, a force is applied so as to incline toward the weight side end portion 34 while being supported by the shaft portion 22. Here, at the opening edge of the drain hole 20 on the weight side end portion 34 side, a stepped-down restricting portion 24 is formed, and the lower surface of the weight side end portion 34 of the opening / closing member 30 is formed on the upper surface of the restricting portion 24. , The weight side end 34 is restricted from being displaced downward from the closed posture (see FIG. 2A).

  As shown in FIGS. 2 to 5, the water storage side end portion 36 of the opening / closing member 30 receives water flowing down from the resonance chamber 12 in the closed posture, and the water storage side end portion 36 rather than the weight side end portion 34. A water storage recess 38 capable of storing an amount of water that becomes heavy is formed. The water storage recess 38 is formed in a concave groove shape that opens upward in the short direction of the water storage side end 36, and is recessed from the bottom of the resonance chamber 12 in the closed position of the opening / closing member 30 (see FIG. 4). ). Moreover, the water storage recessed part 38 is sealed by the hole wall which defines the drain hole 20 in the closed attitude | position of the opening-and-closing member 30, and the water storage recessed part 38 can store water by a closed attitude | position. It is like that. In the water storage recess 38, in the closed position of the opening / closing member 30, a heavier amount of water than the difference weight between the weight side end 34 and the water storage side end 36 can be stored, and water is stored in the water storage recess 38. By accumulating, the water storage side end 36 is configured to be heavier than the weight side end 34. The opening / closing member 30 can discharge water from the water storage recess 38 by tilting to the open posture, and can allow drainage from the resonance chamber 12 through the open drain hole 20.

(Effects of Example)
Next, the operation of the resonator 10 according to the embodiment will be described. The opening / closing member 30 is closed in a normal state where water does not collect in the water storage recess 38 or water remains in the water storage recess 38 but the weight of the water storage side end 36 does not exceed the weight of the weight side end 34. Since the water drain hole 20 is closed while maintaining the normal posture, the resonance chamber 12 is maintained to be a closed space (see FIG. 2A). When the weight of the water storage side end 36 exceeds the weight of the weight side end 34 due to the accumulation of water in the water storage recess 38, the opening / closing member 30 swings from the closed position to the open position with the shaft portion 22 as a fulcrum. Displaces (see FIG. 2B). As a result, the water storage recess 38 of the opening / closing member 30 is inclined obliquely, the sealing state by the hole wall of the drain hole 20 is released, and the water accumulated in the water storage recess 38 is discharged. When there is no (less) water accumulated in the water storage recess 38 and the water storage side end 36 becomes lighter than the weight side end 34, the opening / closing member 30 is displaced from the open position to the closed position and closes the drain hole 20. Return to the normal state (see FIG. 2A).

  In the resonator 10, the drain hole 20 is closed by the opening / closing member 30 in a normal state, and therefore the frequency actually reduced deviates from the set frequency to be reduced set in the design due to the presence of the drain hole 20. Rather, the noise attenuation characteristics as designed are obtained. Thus, the resonator 10 can obtain the noise attenuation characteristics as designed, so that it is not necessary to increase the volume of the resonance chamber 12 as in the case where there is an open drainage hole as described in the conventional example. The whole can be made the minimum size while preventing water from accumulating in 12. Further, since the resonator 10 can close the drain hole 20 with the opening / closing member 30, the resonance chamber 12 can be regarded as a closed space without the drain hole 20, and the design frequency can be set by a simple frequency calculation formula in designing. Can be calculated, and the deviation of the attenuation frequency between the model by analysis and the actual product can be reduced. And in order to match | combine with the design frequency, it does not require the effort which adjusts the position of the drain hole 20, etc., and the cost concerning correction | amendment of a shaping | molding die can be suppressed when shape | molding the resonator 10 by die shaping | molding.

(Example of change)
The present invention is not limited to the configuration of the embodiment described above, and can be modified as follows, for example.
(1) The shaft portion may be provided in the opening / closing member, and the bearing portion may be provided in the resonance chamber.
(2) The outer shape of the opening / closing member may be any shape as long as the drain hole can be closed in a closed posture. For example, the outer shape of the opening / closing member may be circular according to the circular drain hole.

12 resonance chamber, 20 drain hole, 22 shaft portion, 24 regulating portion, 30 opening and closing member,
34 Weight side end (one swing end), 36 Water storage side end (the other swing end), 38 Water storage recess

Claims (2)

A drain hole formed in the bottom of the resonance chamber in a vertical direction;
An opening / closing member that is pivotally supported with respect to the resonance chamber via a shaft portion and that is displaced between a closed posture that closes the drain hole and an open posture that opens the drain hole;
The opening / closing member is formed such that one oscillating end is heavier than the other oscillating end sandwiching the shaft portion, and is held in the closed posture by the weight of the one oscillating end, A water storage recess is formed in the oscillating end portion of the oscillating end portion for receiving water flowing down from the resonance chamber and storing an amount of water in which the other oscillating end portion is heavier than the one oscillating end portion, A resonator configured to be displaced to the open posture by water accumulated in a water storage recess and drain from the water storage recess.   2. The resonator according to claim 1, wherein a restricting portion is provided at an opening edge of the drain hole to restrict one swinging end portion of the opening / closing member from being displaced downward from the closed posture. 3.

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