JP4342348B2 - Combined variable frequency silencer system - Google Patents

Description

  The present invention selectively selects a desired noise frequency according to the rotational speed of an engine intake system noise generated and changed according to the rotational speed of a vehicle engine by means of an engine rotational speed detection device, an arithmetic processing device, and a variable frequency resonance type resonator device. The present invention relates to a variable frequency silencing system (device) for silencing sound.

  A resonance muffler called a resonator is mounted on the intake system of an automobile engine. However, since the resonance muffler can mute only one frequency, if there are a plurality of frequencies to be muffled, a plurality of mufflers are required. Therefore, in order to compensate for the drawbacks such as the number of parts and the space, a variable frequency resonance type resonator device that varies the muffling frequency according to the engine speed or the vehicle speed has been considered, and many variable structures have been proposed (for example, And Patent Documents 1 to 12).

The conventional variable frequency resonance type resonator device has the following problems.
There are two main components of the intake noise: noise that changes in frequency in synchronization with the engine speed (rotational order component) and noise that always occurs at a constant frequency (air column resonance) regardless of the engine speed. However, in the conventional variable frequency resonance type resonator device, only a desired single noise frequency is silenced according to the engine speed or the vehicle speed, and only one of them can be silenced. The noise level is not as great as expected.
JP 2001-50127 A JP 2001-123902 A JP 2000-154725 A JP 2000-337219 A JP-A-10-102621 JP-A-10-153152 JP-A-7-259671 JP-A-7-293377 Japanese Patent Laid-Open No. 10-299451 JP-A-8-158964 JP-A-8-109857 JP-A-8-82260

The problem to be solved by the present invention is that only one of the rotational order component and air column resonance can be silenced.
An object of the present invention is to provide a composite variable frequency silencing system capable of silencing noise (rotational order component) whose frequency changes in synchronization with the engine speed and simultaneously silencing noise (air column resonance) generated at a constant frequency at the same time. Is to provide.

The present invention for achieving the above object is as follows.
(1) A desired noise frequency is selectively silenced according to the number of revolutions of the engine intake system noise generated and changed according to the engine speed of the vehicle by means of an engine speed detection device, an arithmetic processing unit, and a variable frequency resonance type resonator device. A combined variable frequency silencer system,
The variable frequency resonance type resonator device includes: (a) a resonance part , a fixed neck wall , and a member arranged in a movable state in the fixed neck wall; and the cross-sectional area of the fixed neck wall is changed by the member. A composite type having a frequency variable resonator configured as a frequency fixed resonator, the member itself , (b) a drive actuator that drives the frequency fixed resonator, and (c) a position detection unit that detects the position of the frequency fixed resonator. Variable frequency silencer system.
(2) The composite variable frequency silencing system according to (1), wherein the fixed frequency resonator constitutes a neck wall of a variable frequency resonator together with the fixed neck wall.
(3) The composite variable frequency silencer system according to (1), wherein the fixed neck wall and the frequency fixed resonator are arranged in a resonance portion of the frequency variable resonator.
(4) The composite variable frequency silencer system according to (1), wherein the fixed frequency resonator is rotatable with respect to the fixed neck wall.
(5) The composite variable frequency silencer system according to (1), wherein the fixed frequency resonator is linearly movable with respect to the fixed neck wall.

In the composite type variable frequency silencer system of (1) above, the variable frequency resonance type resonator device has a fixed frequency resonator, so that noise (air column resonance) that is always generated at a constant frequency is fixed regardless of the engine speed. Can be muted with a resonator. In addition, since the variable frequency resonance type resonator device has a fixed neck wall and a movable frequency fixed resonator, by moving the frequency fixed resonator with respect to the fixed neck wall, noise that changes in frequency in synchronization with the engine speed (rotation order) Component) can be muted. Therefore, it is possible to mute two frequencies simultaneously.
In the composite variable frequency silencer system of (2) above, a part of the wall constituting the frequency fixed resonator constitutes the neck wall of the frequency variable resonator together with the fixed neck wall.
In the composite variable frequency silencer system of (3) above, when the frequency fixed resonator moves relative to the fixed neck wall, the amount of the frequency fixed resonator entering the space surrounded by the fixed neck wall in the resonance portion changes. Therefore, as the neck cross-sectional area of the frequency variable resonator decreases (increases), the volume of the frequency variable resonator increases (decreases). Therefore, compared with the case where only the neck cross-sectional area or only the volume is variable, the variable range of the silencing frequency is large, and it is possible to quickly respond to the desired silencing frequency.
In the composite variable frequency silencer system of (4), the neck cross-sectional area of the frequency variable resonator can be changed by rotating the frequency fixed resonator. Therefore, a plurality of neck shapes are not necessary. Therefore, space saving can be achieved compared with the case of having a plurality of neck shapes.
In the composite variable frequency silencer system of (5) above, the neck cross-sectional area of the frequency variable resonator can be changed by linearly moving the frequency fixed resonator. Therefore, a plurality of neck shapes are not necessary. Therefore, space saving can be achieved compared with the case of having a plurality of neck shapes.

FIGS. 1-7 has shown the composite type variable frequency silencer system of Example 1 of this invention, and FIGS. 8-10 has shown the composite type variable frequency silencer system of Example 2 of this invention. However, FIG. 1 is also applicable to the second embodiment of the present invention.
Parts common to the first embodiment of the present invention and the second embodiment of the present invention are denoted by the same reference numerals throughout the first embodiment of the present invention and the second embodiment of the present invention.
First, parts common to the first embodiment of the present invention and the second embodiment of the present invention will be described with reference to FIGS. 1 to 3 and FIG. 8, for example.
As shown in FIGS. 1 and 2, the variable frequency silencing system (apparatus) 10 according to the embodiment of the present invention is configured to calculate engine intake system noise generated and changed in accordance with the engine speed of the vehicle and the engine speed detecting device 20 and processing. This is a variable frequency silencing system that selectively silences a desired noise frequency according to the engine speed by the device 30 and the variable frequency resonance type resonator device 40.

  The variable frequency resonance type resonator device 40 includes a frequency variable resonator 41 that includes a resonance unit 42, a fixed neck wall 43, and a frequency fixed resonator 44 that is movable with respect to the fixed neck wall 43, and a drive actuator that drives the frequency fixed resonator 44 ( Motor) 45 and a position detector 46 for detecting the position of the fixed frequency resonator 44.

The resonance part 42 is attached in the middle of the pipe of the engine intake system. As shown in FIG. 2, the resonance unit 42 has a resonance chamber inside. An opening 42a connected to the engine intake system is formed in one wall of the resonance portion 42.
The fixed neck wall 43 is located in the resonance part 42. The fixed neck wall 43 is fixed to the resonance part 42. The fixed neck wall 43 constitutes a part of the neck portion of the frequency variable resonator 41.

The fixed frequency resonator 44 is located in the resonance unit 42. The fixed frequency resonator 44 is movable with respect to the fixed neck wall 43. Here, the movement may be rotational movement or linear movement (slide).
When the frequency fixing resonator 44 moves in the direction of the arrow in FIG. 3 (or FIG. 8) with respect to the fixed neck wall 43, the size of the opening 42a of the resonance portion 42 changes. Therefore, when the fixed frequency resonator 44 moves with respect to the fixed neck wall 43, the neck cross-sectional area of the variable frequency resonator 41 changes.
The frequency fixed resonator 44 has a space (resonance chamber) inside, and has a hole 44a connected to the engine intake system, and an extending portion 44b extending from the edge of the hole 44a to the inside of the frequency fixed resonator 44. The hole 44a and the extending portion 44b constitute a neck portion of the frequency fixing resonator 44. The neck cross-sectional area, the neck length, and the resonance chamber of the fixed frequency resonator 44 are constant.
The fixed frequency resonator 44 constitutes a part of the neck of the variable frequency resonator 41. The fixed frequency resonator 44 and the fixed neck wall 43 constitute a neck portion of the variable frequency resonator 41.

The drive actuator 45 is a motor. The motor moves the fixed frequency resonator 44. The drive actuator 45 moves the fixed frequency resonator 44 based on the signal from the arithmetic processing unit 30.
The position detection unit 46 detects the position of the fixed frequency resonator 44 and feeds back the signal to the arithmetic processing unit 30.

Here, an operation of a part common to the first embodiment of the present invention and the second embodiment of the present invention will be described. As shown in FIG. 1, the rotational speed detection device 20 detects the rotational speed of the engine 50 and sends the signal to the arithmetic processing device 30. The position detector 46 detects the position (rotation angle) of the fixed frequency resonator 44 and feeds back the signal to the arithmetic processing unit 30. The arithmetic processing unit 30 determines the position (rotation angle) of the frequency fixed resonator 44 based on the signal from the position detection unit 46, and the position of the frequency fixed resonator 44 detected by the position detection unit 46 (position before movement). ) To determine how much the drive actuator 45 is to be moved. The drive actuator 45 (motor) rotates based on a signal from the arithmetic processing device 30. The fixed frequency resonator 44 moves as the motor rotates.
When the fixed frequency resonator 44 moves and the position of the fixed frequency resonator 44 reaches a target value, the arithmetic processing unit 30 outputs a motor stop signal to the drive actuator 45, and the motor stops based on the signal. Since the motor stops, the movement of the fixed frequency resonator 44 stops.
When the position of the fixed frequency resonator 44 is at the target value, the variable frequency resonator 41 silences a desired noise frequency. When the position of the fixed frequency resonator 44 is at the target value, the hole 44a of the fixed frequency resonator 44 overlaps the opening 42a, and the fixed frequency resonator 44 silences noise generated at a constant frequency.

As shown in FIGS. 3 and 8, since the variable frequency resonance type resonator device 40 has a fixed frequency resonator 44, noise (air column resonance) that is always generated at a constant frequency regardless of the engine speed is fixed in the frequency fixed resonator. 44 can mute. Further, since the neck portion of the variable frequency resonator 41 is constituted by the fixed frequency resonator 44 and the fixed neck wall 43, the noise whose frequency changes in synchronization with the engine speed when the fixed frequency resonator 44 moves relative to the fixed neck wall 43. (Rotation order component) can be muted. Therefore, it is possible to mute two frequencies simultaneously.

The relationship among the muffling frequency, the sound speed, the neck length, the volume, and the neck cross-sectional area is expressed by equation (a).
f = (c / 2π) {S / (L · V)} ^1/2 (a)
However,
f (Hz): muffling frequency c: sound velocity L: neck length V: volume S: neck cross-sectional area.
In the embodiment of the present invention, when the fixed frequency resonator 44 moves relative to the fixed neck wall 43, the amount of the fixed frequency resonator 44 that enters the space that the fixed neck wall 43 surrounds in the resonance portion 42 changes. Therefore, as the neck cross-sectional area of the frequency variable resonator 41 decreases (increases), the volume of the resonance portion 42 of the frequency variable resonator 41 increases (increases) conversely. That is, as the numerator on the right side of the equation (a) becomes smaller (becomes larger), the denominator on the right side of the equation (a) becomes larger (becomes smaller). Therefore, compared with the case where only the neck cross-sectional area or only the volume is variable, the variable range of the silencing frequency is large, and it is possible to quickly respond to the desired silencing frequency.

Since the neck cross-sectional area and volume of the frequency variable resonator 41 can be changed by moving the frequency fixed resonator 44, the silencing frequency can be changed by using the neck cross-sectional area and the volume. Therefore, the variable range of the silencing frequency is large compared to the case where the silencing frequency is changed by any one of the neck cross-sectional area, the neck length, and the volume. Since the variable range of the silencing frequency is large, even if the amount of moving the fixed frequency resonator 44 is small, the variable range of the silencing frequency is large, and it is possible to quickly respond to the desired silencing frequency simply by rotating the motor.
Further, since the neck cross-sectional area and the volume can be changed by moving the frequency fixed resonator 44, a plurality of neck shapes are unnecessary. Therefore, space saving can be achieved compared with the case of having a plurality of neck shapes.

Next, parts unique to each embodiment of the present invention will be described.
[Invention Example 1] (FIGS. 1 to 7)
In the first embodiment of the present invention, a case where the fixed frequency resonator 44 is rotatable with respect to the fixed neck wall 43 is shown.

As shown in FIGS. 2 and 3, the opening 42 a of the resonance part 42 has a semicircular shape with the center P as the center.
As shown in FIGS. 3 and 4, the fixed neck wall 43 includes a fixed neck wall A 43 a and a fixed neck wall B 43 b.
The shape of the fixed neck wall A43a is a semi-cylindrical shape with the center P as the center. The fixed neck wall A43a is fixed to the radially outer end of the opening 42a (the entire arc-shaped edge of the opening 42a).
The shape of the fixed neck wall B43b is a flat plate shape. The fixed neck wall B43b is formed integrally with the fixed neck wall A43a, or is formed separately from the fixed neck wall A43a and fixedly attached to the fixed neck wall A43a. The fixed neck wall B43b extends from one side in the circumferential direction of the semi-cylindrical fixed neck wall A43a to the center P in the radial direction of the fixed neck wall A43a.

The fixed frequency resonator 44 is rotatable about the center P with respect to the fixed neck wall 43. As shown in FIG. 2, the fixed frequency resonator 44 is coupled to the drive actuator 45 by a rotating shaft 45a.
As shown in FIGS. 3 and 5, the frequency fixed resonator 44 includes a cylindrical portion 44c, first and second semicircular portions 44d and 44e, and a flat plate portion 44f.
The cylindrical portion 44c has a semicylindrical shape with the center P as the center.
The first semicircular portion 44d is disposed at one end in the axial direction of the cylindrical portion 44c (the end on the opening 42a side). The first semicircular portion 44d has the same shape (including substantially the same) as the opening 42a, and has a semicircular shape centered on the center P. Since the first semicircular portion 44d has the same shape as the opening 42a, the size of the opening 42a decreases as the angle at which the frequency fixing resonator 44 rotates around the center P increases. The hole 44a is provided in the first semicircular portion 44d.

The second semicircular portion 44e is disposed at the other axial end of the cylindrical portion 44c. The second semicircular portion 44e has the same shape (or substantially the same shape) as the opening 42a, and has a semicircular shape centered on the center P.
The flat plate portion 44f closes the opening of the space formed by the cylindrical portion 44c, the first semicircular portion 44d, and the second semicircular portion 44e.
The portion excluding the neck portion composed of the hole 44a and the extending portion 44b from the space surrounded by the cylindrical portion 44c, the first semicircular portion 44d, the second semicircular portion 44e, and the flat plate portion 44f is a frequency. This is a resonance chamber of the fixed resonator 44.

The operation and effect of Embodiment 1 of the present invention will be described.
As the angle at which the frequency fixing resonator 44 rotates with respect to the fixed neck wall 43 increases, the opening 42a becomes smaller. Therefore, the neck cross-sectional area of the frequency variable resonator 41 is reduced.
Here, the variable frequency resonance type resonator device 40 is mounted in the middle of the pipe line 60 that is assumed to be an intake system as shown in FIG. 6, and the frequency fixed resonator 44 is arranged around the axis P with respect to the fixed neck wall 43. FIG. 7 shows the silencing frequency at the positions of the three patterns (rotation angle 20 °, rotation angle 70 °, rotation angle 120 °) when rotated in the arrow direction. As shown in FIG. 7, by changing the angle, the neck cross-sectional area and the volume of the frequency variable resonator 41 are changed, and the silencing frequency can be varied. Further, since the fixed frequency resonator 44 is provided, noise (air column resonance) generated at a constant frequency regardless of the engine speed can be silenced by the fixed frequency resonator 44.

[Invention Example 2] (FIGS. 8 to 10)
In the second embodiment of the present invention, the case where the frequency fixing resonator 44 is linearly movable with respect to the fixed neck wall 43 is shown.

The opening 42a of the resonance part 42 is rectangular.
As shown in FIG. 9, the fixed neck wall 43 has a fixed neck wall C43c, a fixed neck wall D43d, and a fixed neck wall E43e. The shapes of the fixed neck wall C43c, the fixed neck wall D43d, and the fixed neck wall E43e are flat plate shapes. The fixed neck wall C43c, the fixed neck wall D43d, and the fixed neck wall E43e are fixed to the edge of the opening 42a of the resonance portion 42. The fixed neck wall C43c and the fixed neck wall D43d are opposed to each other. The fixed neck wall E43e connects the fixed neck wall C43c and the fixed neck wall D43d.

The fixed frequency resonator 44 can linearly move (slide) in a direction approaching / separating from the fixed neck wall E43e. The fixed frequency resonator 44 can enter and exit between the fixed neck wall C43c and the fixed neck wall D43d.
The frequency fixed resonator 44 is a rectangular parallelepiped. The hole 44 a is provided in one wall of the frequency fixed resonator 44 on the opening 42 a side.

The operation and effect of Embodiment 2 of the present invention will be described.
When the frequency fixing resonator 44 approaches the fixed neck wall E43e, the opening 42a becomes small. Therefore, the neck cross-sectional area of the frequency variable resonator 41 is reduced.

1 is a block diagram of a composite variable frequency silencing system of Embodiment 1 of the present invention. It is a see-through | perspective perspective view of the composite type variable frequency silencer system of Example 1 of this invention. It is an expansion see-through | perspective perspective view which shows the opening of a resonance part, a fixed neck wall, and a frequency fixed resonator of the composite type variable frequency silencer system of Example 1 of this invention. It is an expansion see-through | perspective perspective view which shows the opening of a resonance part, and a fixed neck wall of the composite type variable frequency silencer system of Example 1 of this invention. It is an expansion see-through | perspective perspective view which shows the frequency fixed resonator of the composite type variable frequency silencer system of Example 1 of this invention. It is a perspective view which shows the state which mounted | worn with the variable frequency resonance type | mold resonator device of the composite type variable frequency silencer system of Example 1 of this invention in the middle of the pipe line made to be considered to be an intake system. FIG. 7 is a graph of acoustic transfer characteristics versus frequency when the rotation angle of the frequency fixed resonator is varied in the state of FIG. 6. It is an expansion see-through | perspective perspective view which shows the opening of a resonance part, a fixed neck wall, and a frequency fixed resonator of the composite type variable frequency silencer system of Example 2 of this invention. It is an expansion see-through | perspective perspective view which shows the opening of a resonance part and the fixed neck wall of the composite type variable frequency silencer system of Example 2 of this invention. It is an expansion see-through | perspective perspective view which shows the frequency fixed resonator of the composite type variable frequency silencer system of Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Variable frequency silencer system 20 Rotational speed detection apparatus 30 Arithmetic processing apparatus 40 Variable frequency resonance type resonator apparatus 41 Frequency variable resonator 42 Resonance part 42a Resonance part opening 43 Fixed neck wall 44 Frequency fixed resonator 44a Frequency fixed resonator hole 44b Frequency fixed Resonator extension 45 Drive actuator 46 Position detector 50 Engine 60 Pipe line

Claims (5)

A composite type that selectively silences a desired noise frequency according to the number of revolutions of the engine intake system noise generated and changed according to the engine speed of the vehicle by means of an engine speed detector, an arithmetic processing unit, and a variable frequency resonance type resonator device. A variable frequency silencer system,
The variable frequency resonance type resonator device includes: (a) a resonance part , a fixed neck wall , and a member arranged in a movable state in the fixed neck wall; and the cross-sectional area of the fixed neck wall is changed by the member. A composite type having a frequency variable resonator configured as a frequency fixed resonator, the member itself , (b) a drive actuator that drives the frequency fixed resonator, and (c) a position detection unit that detects the position of the frequency fixed resonator. Variable frequency silencer system.   2. The composite variable frequency silencer system according to claim 1, wherein the fixed frequency resonator constitutes a neck wall of a variable frequency resonator together with the fixed neck wall.   The composite variable frequency silencer system according to claim 1, wherein the fixed neck wall and the frequency fixed resonator are disposed in a resonance portion of the frequency variable resonator.   The composite variable frequency silencer system according to claim 1, wherein the fixed frequency resonator is rotatable with respect to the fixed neck wall.   2. The composite variable frequency silencer system according to claim 1, wherein the fixed frequency resonator is linearly movable with respect to the fixed neck wall.

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