JP2008213734A - Noise reduction system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a noise reduction system for a vehicle capable of outstandingly reducing noise by vibration transmitted from a tire into a cabin, especially noise caused by tire cavity resonance. <P>SOLUTION: The noise reduction system for the vehicle is provided with a suspension support 10 interposed between a rod 22 of a shock absorber 20 and a vehicle body 12; a vibration sensor 82 mounted to an axle part 84 at a tire side than the support and detecting vibration at a predetermined frequency area of the axle part; and a vibration exciter 14 mounted to the vehicle body 12 and capable of vibrating the vehicle body. The vibration exciter 14 is driven/controlled based on a signal from a vibration sensor 82 to vibrating the vehicle body 12, thereby, air in the cabin 18 is oscillated to reduce the sound in the cabin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a noise reduction system that can reduce noise in a passenger compartment of a vehicle such as an automobile.

  In recent automobiles, especially high-end passenger cars, the level of demand for quietness is increasing, and noise reduction caused by vibration from the engine can be reduced by, for example, attaching an actuator to an engine mount that supports the engine with respect to the vehicle body. There has been proposed a technique for reducing the noise in the passenger compartment by generating a control vibration having an opposite phase that cancels the engine vibration from the actuator (see, for example, Patent Document 1 below).

  However, in order to further reduce the noise, not only the vibration from the engine but also the road noise, which is the noise caused by the vibration transmitted from the tire to the vehicle interior, is required to be further reduced. Among such road noises, noise resulting from tire cavity resonance is a relatively low amplitude and annoying noise, and its reduction is desired.

In order to reduce the noise caused by the cavity resonance of the tire, in Patent Documents 2 to 4 below, a vibration support means is provided on a suspension support disposed at a connection portion between the rod of the shock absorber and the vehicle body. Proposed. In the techniques disclosed in these documents, vibration in the axial direction of the rod is detected, and the rod is vibrated by an actuator so as to cancel the vibration of the rod based on the signal. In this case, the output of the actuator is matched with the output of the rod to cancel the vibration. However, it is not easy to match both outputs, and further reduction of noise in the vehicle interior is required.
JP-A-6-16047 JP 2006-282117 A JP 2006-282118 A JP 2007-015471 A

  The present invention has been made in view of the above, and provides a vehicle noise reduction system capable of reducing noise caused by vibration transmitted from a tire to a vehicle interior, particularly noise caused by tire cavity resonance. Objective.

  A vehicle noise reduction system according to the present invention includes a vibration isolation device including a vibration isolation base made of a rubber-like elastic body that is interposed between a wheel side member and a vehicle body and connects the wheel side member and the vehicle body, A vibration detection unit that is attached to the wheel side member and detects vibrations in a predetermined frequency range of the wheel side member; and a vibration device that is attached to the vehicle body and can vibrate the vehicle body. . Then, the vibration control device is driven and controlled based on a signal from the vibration detection means, and the vehicle body is vibrated to vibrate the air in the vehicle interior to reduce the sound in the vehicle interior. is there. Here, the wheel side member refers to a member on the wheel side of the vibration isolating base of the vibration isolator.

  In this system, the vibration of the wheel side member is detected by the vibration detection means attached to the wheel side member, and the vehicle body is vibrated by the vibration device based on the detected signal. By vibrating the vehicle body, it is possible to generate sound by vibrating the air in the vehicle interior, so the vehicle body is oscillated so that the noise in the vehicle interior caused by the vibration of the wheel side member is canceled by this sound. By shaking, the noise in the passenger compartment can be reduced. At this time, since the vibration detection means is attached to the wheel side member to detect the vibration of the wheel side member, the vibration caused by the cavity resonance of the tire can be reliably detected. In addition, the noise generated by vibrating the vehicle body directly cancels the vehicle interior noise caused by the vibration of the wheel-side member, so that the noise reduction effect is excellent. In addition, compared with the case where noise is canceled by a speaker provided in the vehicle interior, the mounting position is more flexible (because it is not always necessary to expose the vehicle interior so that the vehicle body is vibrated), the noise alone Not only can vibration be reduced at the same time.

  Here, since the vibration sound caused by the cavity resonance of the tire has a normal frequency around 200 Hz (for example, 200 to 250 Hz), the vibration control device is driven and controlled so as to cancel the vibration in the frequency range of 100 to 350 Hz. Further, it is possible to effectively reduce the noise in the passenger compartment due to the cavity resonance.

  The first vibration device according to the present invention includes a shaft member as a mover, a stator that is provided on an outer peripheral side of the shaft member and supports the shaft member so as to reciprocate in the axial direction, and the stator. A cylindrical housing member that is housed and held inside, and a tip end portion of the shaft member is fixed to the vehicle body, and the housing member is disposed on the outer peripheral side of the fixed portion of the shaft member with respect to the vehicle body. It is fixed to. With this configuration, the vehicle body can be directly vibrated by reciprocating the shaft member in the axial direction.

  In the first vibration exciter, the vibration isolator is a suspension support interposed between a rod of a shock absorber and a vehicle body, and a through hole through which an upper end portion of the rod is inserted has the vehicle body A down-facing hook-shaped member that forms a downwardly opened recess that accommodates the upper end portion of the rod inserted through the through hole is attached to the vehicle body so as to close the through hole, and the shaft The lower end part of a member may be fixed to the ceiling surface of the prone ridge member. Thereby, the upper space of the suspension support can be used effectively.

  The second vibration device according to the present invention includes a shaft member as a mover, a stator that is provided on an outer peripheral side of the shaft member and supports the shaft member so as to reciprocate in the axial direction, and the stator. A cylindrical housing member accommodated and held inside, the housing member is fixed to the vehicle body, and a mass body is attached to the tip of the shaft member inside the housing member, The vehicle body is configured to be excited by vibrating the mass body. By comprising in this way, a vehicle body can be vibrated effectively by reciprocating a shaft member to an axial direction.

  In the second vibration exciter, the lower end of the housing member is fixed to the upper surface of the vehicle body, the upper end opening is closed by the top plate, and the stator is suspended from the top plate. In addition, the mass body may be coupled to the vehicle body via a rubber-like elastic body inside the fixing portion of the housing member with respect to the vehicle body. Alternatively, the mass body may be coupled to the inner peripheral surface of the housing member via a rubber-like elastic body.

  In the present invention, the vibration isolator is a suspension support interposed between a rod of a shock absorber and a vehicle body, and the suspension support is a cylindrical inner mounting member attached to the upper end portion of the rod; An outer mounting member that surrounds the inner mounting member and is mounted on the vehicle body side, and the vibration-proof base that connects the inner mounting member and the outer mounting member, and the inner mounting member projects radially outward. And the vibration device is provided on the outer periphery of the shaft member as a mover and supports the shaft member so as to be capable of reciprocating in the axial direction. A flange that protrudes radially outward from the lower end portion of the cylindrical portion, and a cylindrical portion that surrounds the upper end portion of the inner mounting member is coupled to the lower end portion of the shaft member. The vibration plate is provided facing the upper portion of the flange portion, the vibration plate is embedded in the vibration isolation substrate, and the vibration isolation substrate is disposed between the lower surface of the vibration plate and the upper surface of the flange portion. A part may be interposed.

  ADVANTAGE OF THE INVENTION According to this invention, the noise resulting from the vibration transmitted from a tire to a vehicle interior, especially the noise in a vehicle interior resulting from tire cavity resonance can be reduced effectively.

  Next, embodiments of the present invention will be described with reference to the drawings.

  1 is a cross-sectional view of a suspension support constituting an automobile noise reduction system according to a first embodiment of the present invention, FIG. 2 is a schematic view of an automobile incorporating the system, FIG. 3 is an enlarged view of a main part thereof, and FIG. Is a block diagram of the system.

  In the present embodiment, the vibration device 14 is incorporated in the attachment portion of the suspension support 10 of the automobile to the vehicle body 12 to reduce noise transmitted from the tire 16 into the vehicle interior 18, particularly noise caused by cavity resonance of the tire 16. The present invention relates to a noise reduction system.

  This system includes a suspension support (upper support) 10 that is an anti-vibration device interposed between the rod 22 of the shock absorber 20 and the vehicle body 12, and an acceleration that is attached to the vehicle body 12 and can vibrate the vehicle body 12. And a vibration device 14.

  The suspension support 10 includes a cylindrical inner attachment member 24 attached to the upper end portion 22a of the rod 22 of the shock absorber 20, and an outer attachment member 26 attached to the vehicle body 12 which is a concept including a vehicle body panel, a frame, and a connecting member for these. And an anti-vibration base 28 made of a rubber-like elastic body that is disposed between the inner mounting member 24 and the outer mounting member 26 and connects the two.

  The inner mounting member 24 has an upper end 22 a of the rod 22 inserted through a hollow portion thereof, and the upper end 22 a is fastened and fixed by a nut 30. A flange portion 32 projecting radially outward is provided at an axially intermediate portion of the cylindrical body of the inner mounting member 24, and the flange portion 32 is embedded in the vibration isolation base 28.

  The outer mounting member 26 is a member surrounding the outer periphery of the inner mounting member 24, and is a disk-shaped metal plate member that is mounted so as to close the circular through hole 34 provided in the vehicle body 12 from the lower surface side. 36 and a metal cup-shaped member 38 attached to the lower surface of the outer peripheral portion of the plate member 36. The plate member 36 includes an insertion hole 36a through which the upper portion of the inner mounting member 24 is inserted at the center thereof, and is fixedly attached to the lower peripheral portion of the through hole 34 of the vehicle body 12 by a bolt 40 and a nut 42 at the outer peripheral portion thereof.

  The cup-shaped member 38 has a container shape that opens upward, and an insertion hole 38a through which the rod 22 is inserted is provided at the center of the bottom wall. Further, the opening edge portion at the upper end of the cup-shaped member 38 is formed as a flange portion 38 b extending outward, and the flange portion 38 b is overlapped with the outer peripheral portion of the plate member 36 and fixed by the bolt 40 and the nut 42. By combining the plate member 36 and the cup-shaped member 38 in this way, a housing space for the vibration-proofing base 28 is formed between the two, and by housing the vibration-proofing base 28 in the housing space, the inner side The mounting member 24 and the outer mounting member 26 are elastically coupled to each other via a vibration isolation base 28.

  As the vibration device 14, various pneumatic, hydraulic, and electronic actuators can be used as long as they can vibrate the vehicle body 12. In this example, a linear actuator 44 driven by an electromagnet is used. As the actuator 44, those described in Patent Documents 2 to 4 can be used.

  That is, the actuator 44 includes a shaft member 46 as a mover, and a stator 48 that is provided on the outer peripheral portion of the shaft member 46 and supports the shaft member 46 so as to reciprocate in the axial direction X. This is an iron core movable actuator.

  The shaft member 46 is provided with a magnetic material portion 50 formed by laminating a large number of metal plates made of a magnetic metal such as an electromagnetic steel plate on the outer peripheral surface in the axial intermediate portion, and a pair of upper and lower leaf springs 52, The inner space of the stator 48 is connected to and supported by an axial direction (vertical direction) X via 52.

  The stator 48 is formed by laminating a large number of annular metal plates made of a magnetic metal, and is opposed to the yoke 54 surrounding the shaft member 46 so that the shaft member 46 is sandwiched between the yoke 54 and the central portion of the yoke 54. Has a magnetic pole portion 56 projecting radially inward. The magnetic pole portion 56 is provided with at least a pair of permanent magnets 58 and 58 that are adjacent to each other in the axial direction X and have different polarities. A coil 60 capable of generating a magnetic flux passing through the pair of permanent magnets 58 and 58 is wound around the magnetic pole portion 56.

  As a result, the stator 48 causes the shaft member 46 to move in the forward stroke and the backward stroke in the axial direction X by a combination of the magnetomotive force generated by the excitation of the coil 60 and the magnetomotive force of each permanent magnet 58. It is configured to drive in both directions. That is, the movable iron core type actuator 44 can move the shaft member 46 up and down by passing a sine wave alternating current through the coil 60, and gives a vibration of a sine wave curve to the member connected thereto. It is configured to be able to.

  The vibration device 14 includes a cylindrical housing member 62 that accommodates and holds the actuator 44 including the stator 48 inside. The housing member 62 is provided with a mounting flange 64 projecting radially outward at the lower end thereof, and together with the plate member 36 and the cup-shaped member 38 at the mounting flange 64, the bolt 40 and the nut 42 are used for the vehicle body 12. The through hole 34 is fixed to the upper surface side.

  The upper end opening of the housing member 62 is closed by a top plate portion 68 fixed by bolts 66, and a stator 48 is suspended from the top plate portion 68. That is, the stator 48 is fastened and fixed to the lower surface of the top plate portion 68 by the bolt 70 at the outer peripheral portion thereof.

  On the other hand, the shaft member 46, which is a mover, has a lower end portion 46 a fixed to the vehicle body 12 inside the housing member 62. More specifically, a prone hook-like member 74 that forms a downwardly opened recess 72 that accommodates the inserted rod upper end 22a is inserted into the through hole 34 of the vehicle body 12 through which the rod upper end 22a is inserted. It is attached to the vehicle body 12 so as to close the through hole 34. And the lower end part 46a of the shaft member 46 is being fixed to the ceiling surface of the prone ridge-shaped member 74. As shown in FIG. In this example, the hoop-like member 74 includes a lower body fitting 74a attached to the vehicle body 12, and an upper connecting fitting 74b that constitutes the ceiling surface. The connecting metal fitting 74 b has a convex portion 75 protruding upward at the center, and the lower end portion 46 a of the shaft member 46 is fixed to the upper surface of the convex portion 75.

  The shaft member 46 can be fixed to the connection fitting 74b by fastening and fixing using a bolt or the like, but in this example, it is performed by attracting and fixing a magnet provided on at least one of the joint surfaces of both. Specifically, permanent magnets 76, 76 having a large magnetic force made of neodymium steel or the like are provided on both the lower end portion 46a of the shaft member 46 and the upper surface of the coupling metal piece 74b, and are attracted to each other. Fixed. By fixing using the magnet in this way, when the vibration device 14 is assembled to the vehicle body 12, strict centering between the shaft member 46 and the vehicle body 12 (particularly, the connecting member 74b) is unnecessary. And can be easily combined.

  The housing member 62 is fixed to the vehicle body 12 on the outer peripheral side of the fixing portion of the shaft member 46 with respect to the vehicle body 12. In this way, the housing member 62 on the stator 48 side and the shaft member 46 that is a mover are attached and fixed to the vehicle body 12 to reciprocate the shaft member 46 in the axial direction X. 12 can be directly excited.

  The top plate portion 68 of the housing member 62 is provided with a through hole 78 on the axis of the shaft member 46, and the through hole 78 is closed with a plug member 80 made of a rubber-like elastic body. . The plug member 80 includes a circumferential groove 81 in the peripheral wall portion, and is fitted by being press-fitted into the through hole 78 of the top plate portion 68 from above. Thereby, the penetration | invasion of the water and a foreign material to the inside of the vibration apparatus 14 can be avoided, and damage to a needle | mover or a coil can be prevented.

  The noise reduction system according to the present embodiment is a vibration sensor (acceleration sensor) 82 as a vibration detection unit that detects vibrations in a predetermined frequency range of the member of the suspension support 10 on the wheel side of the vibration isolation base 28. Is provided. In this example, the vibration sensor 82 is attached to the base portion of the tire 16, that is, the axle portion 84 as shown in FIG. 3, and has a predetermined frequency range in the vertical direction of the axle portion 84 (same as the axial direction X). It is configured to detect vibration (specifically, 100 to 350 Hz) and output this as a reference signal. The vibration sensor 82 is connected to a reference signal A / D 86 that is a converter that converts the reference signal from an analog value to a digital value.

  The system further includes a drive signal generator 88 that generates a drive signal based on a signal from the vibration sensor 82, vibration detected by the vibration sensor 82, and noise generated in the vehicle interior due to the vibration. And a storage unit 90 that stores the relationship.

  The drive signal generation unit 88 generates a drive signal for driving and controlling the actuator 44 based on the digital signal input from the reference signal A / D 86, and is configured by a known DSP (digital signal processor). Has been. In the storage unit 90, the relationship between the detection data from the vibration sensor 82 and the sound in the passenger compartment 18 is measured and stored in advance. The drive signal generation unit 88 refers to the storage unit 90 and generates a drive signal for driving and controlling the actuator 44 so as to give the vehicle body 12 vibration that cancels noise in a predetermined frequency region in the passenger compartment 18. Generate. That is, the actuator 44 is controlled so that the vibration device 14 generates a sound having the same phase and the same amplitude as the noise.

  The drive signal output from the drive signal generation unit 88 is converted into an analog signal by a drive signal D / A 92 which is a converter for converting a digital value into an analog value, and further, for driving an actuator by an amplifier 94 such as a power amplifier. Is amplified (for example, 30 to 100 times) and then input to the actuator 44. As a result, the vibration device 14 vibrates the vehicle body 12 to vibrate the air in the passenger compartment 18 to reduce the sound in the passenger compartment 18.

  In addition to the above, the system of the present embodiment includes a microphone 96 as sound detection means for detecting sound in the passenger compartment 18. As shown in FIG. 2, the microphone 96 is provided in the passenger compartment 18 and outputs it as an error signal. The error signal is converted from an analog value to a digital value by the error signal A / D 98 and input to the drive signal generation unit 88. The drive signal generation unit 88 generates the drive signal in consideration of not only the reference signal but also an error signal.

  In the present embodiment configured as described above, the vibration sensor 82 attached to the axle portion 84 detects vibrations in a predetermined frequency range while the vehicle is running, and the vibration device 14 is based on the detected signal. Thus, the vehicle body 12 is vibrated. By vibrating the vehicle body 12, it is possible to generate a sound by vibrating the air in the passenger compartment 18, so that the noise in the passenger compartment 18 due to the vibration of the axle portion 84 can be canceled by this sound. It is possible to reduce the noise in the passenger compartment 18. In particular, by controlling the drive of the actuator 44 so as to cancel noise in the frequency range of 150 to 250 Hz, it is possible to effectively reduce noise in the vehicle interior caused by cavity resonance.

  In the present embodiment, since the vibration sensor 82 is attached to the wheel-side axle portion 84, vibration caused by cavity resonance of the tire 16 can be reliably detected. Further, since the noise in the passenger compartment 12 caused by the vibration of the axle portion 84 is directly canceled by the sound generated when the vehicle body 12 is vibrated, the noise reduction effect is excellent.

  In the present embodiment, the portion that functions as the upper support of the suspension support 10 is provided on the lower surface side of the vehicle body 12, and the vibration device 14 is disposed on the upper surface side of the vehicle body 12. The vibration device 14 can be mounted by effectively using the space above the through hole 34, and the space efficiency is excellent.

  FIG. 5 shows the vibration device 100 according to the second embodiment. The vibration device 100 is different from the vibration device 14 of the above-described embodiment in that the vibration device 100 is provided not on the suspension support 10 but on another body part. As long as the vibration device 100 vibrates the vehicle body 12 and can vibrate the air in the passenger compartment 18 to generate sound, the mounting position is not particularly limited.

  In this example, a reinforcing plate 102 is superimposed on the lower surface of the vehicle body 12, and a housing member 62 is fixed to the vehicle body 12 with bolts 104 and nuts 106 together with the reinforcing plate 102. A columnar connecting member 108 is fastened and fixed to the lower end portion of the shaft member 46 of the actuator 44, and the lower end of the connecting member 108 is inserted into a through hole 110 provided in the vehicle body 12 and the reinforcing plate 102 and fastened and fixed by a nut 112. Has been. Other configurations are basically the same as those of the vibration exciter 14, and the same reference numerals are given and the description thereof is omitted.

  Also in the vibration apparatus 100 of this example, the vehicle body 12 can be directly vibrated by electrically driving and controlling the actuator 44, and the same effect as the first embodiment can be obtained.

  FIG. 6 shows the vibration device 120 according to the third embodiment. The vibration device 120 is different from the vibration devices 14 and 100 of the above-described embodiment in that a metal mass body 122 is attached to the lower end portion 46 a of the shaft member 46 inside the housing member 62.

  In this case, the mass body 122 becomes a mass, and the vehicle body 12 on the fixed side is vibrated by the inertial force by vibrating the mass body 122. In this example, the mass body 122 is formed in a thick disk shape having a diameter substantially equal to that of the stator 48. The outer peripheral surface of the mass body 122 is coupled to the inner peripheral surface of the housing member 62 via a rubber-like elastic body 124. By coupling through the rubber-like elastic body 124 in this way, an undesired movement in the radial direction of the mass body 122 is restricted, and a smooth movement in the axial direction X of the shaft member 46 can be ensured.

  Other configurations are basically the same as those of the vibration exciter 14, and the same reference numerals are given and the description thereof is omitted. Also in this vibration device 120, by electrically driving and controlling the actuator 44, the vehicle body 12 can be directly vibrated, and the same effect as the first embodiment can be obtained.

  FIG. 7 shows a vibration exciter 130 according to the fourth embodiment. The vibration device 130 is different from the vibration device 120 according to the third embodiment in that the mass body 122 is coupled to the vehicle body 12 via a rubber-like elastic body 132.

  That is, in this example, the lower surface of the mass body 122 and the upper surface of the vehicle body 12 facing the lower surface are joined by a rubber-like elastic body 132 interposed therebetween. Other configurations are basically the same as those of the vibration device 120, and the same reference numerals are given and description thereof is omitted. In this vibration exciter 130, by electrically driving and controlling the actuator 44, the vehicle body 12 can be directly vibrated, and the same effects as those of the first embodiment can be achieved.

  FIG. 8 shows the suspension support 10 including the vibration device 140 according to the fifth embodiment. In this example, a cylindrical tube portion 142 surrounding the upper end portion of the inner attachment member 24 is connected to the lower end portion 46a of the shaft member 46 in the vibration exciter 140 so as to face downward. A flange-like vibration plate 144 that protrudes from the lower end portion of the cylindrical portion 142 to the radially outer side Y1 is provided facing the upper portion of the flange portion 32. The vibration plate 144 is embedded in the vibration isolation base 28, whereby a vibration isolation base portion 28 a is interposed between the lower surface of the vibration plate 144 and the upper surface of the flange portion 32.

  A second cylinder portion 146 surrounding the outer peripheral surface of the flange portion 32 of the inner mounting member 24 is connected to the outer peripheral edge portion of the vibration plate 144, and the outer peripheral surface of the flange portion 32 and the second cylindrical portion 146 are arranged inside the second cylindrical portion 146. Another anti-vibration base portion 28b connected to the anti-vibration base portion 28a is interposed between the peripheral surface and the peripheral surface. Other configurations are basically the same as those of the first embodiment, and the same reference numerals are given and description thereof is omitted.

  In the vibration device 140 of this example, the vibration plate 144 vibrates the flange portion 32 by the reciprocating motion of the shaft member 46 in the axial direction. Since the flange portion 32 is connected to the rod 22 and the rod 22 is contained in the oil in the shock absorber 20, when the rod 22 moves up and down, friction is generated due to the damping effect of the oil. Therefore, the vehicle body 12 is indirectly excited by the mass of the rod 22 and the reaction force of the friction.

  Since the vehicle body 12 can be vibrated in this way, the air in the passenger compartment 18 is vibrated by the vibration, and a sound that cancels out the noise in the passenger compartment 18 due to the vibration of the axle portion 84 is generated. As a result, the noise in the passenger compartment 18 can be reduced as in the first embodiment. In this way, when the vehicle body 12 is vibrated, it may be indirectly excited, but it is preferable to directly vibrate the vehicle body 12 as in the first to fourth embodiments.

  Further, in this embodiment, the shaft member 46 includes the cylindrical portion 142, and the upper end portion 22a of the rod 22 is accommodated therein. Therefore, the lower end portion 46a of the shaft member 46 is used as the upper end portion 22a of the rod 22. It can approach and the height of the vibration apparatus 140 can be made low.

  About the noise reduction system of the above embodiment, in order to confirm the effect, the noise reduction confirmation test in the actual vehicle was implemented. At that time, control using the vibration exciter 14 was performed on the four wheels on the front, rear, left and right of the automobile. The control frequency range is 100 to 350 Hz, and the sound pressure level in the passenger compartment is measured when the actuator 44 is driven and controlled by the drive signal from the drive signal generator 88 (actuator ON) and when it is not controlled (actuator OFF). did. The result is as shown in FIG. 9, and by controlling the actuator 44, noise around 214 Hz and 229 Hz due to cavity resonance was significantly reduced. The vertical axis in the graph of FIG. 9 is the power spectral density at the speaker level, and is obtained by applying the A characteristic correction described in JIS C1509 to the sound pressure with respect to the lowest reference sound pressure (20 μPa).

  As described above, according to the present embodiment, it is possible to effectively reduce the noise in the passenger compartment caused by the cavity resonance of the tire 16.

  The present invention can be used mainly for reducing vibration in a passenger compartment of an automobile such as a passenger car.

Sectional drawing of the suspension support which comprises the motor vehicle noise reduction system which concerns on 1st Embodiment of this invention. Conceptual diagram of an automobile with the system installed Conceptual diagram around the tire showing the configuration of the system Block diagram of the system Sectional drawing of the vibration apparatus which concerns on 2nd Embodiment Sectional drawing of the vibration apparatus which concerns on 3rd Embodiment Sectional drawing of the vibration apparatus which concerns on 4th Embodiment Sectional drawing of the suspension support containing the vibration apparatus which concerns on 5th Embodiment Graph showing results of noise reduction confirmation test

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Suspension support (vibration isolator), 12 ... Vehicle body, 14 ... Excitation device, 18 ... Vehicle compartment, 20 ... Shock absorber, 22 ... Rod, 22a ... Upper end part of rod, 24 ... Inner attachment member, 26 ... Outer Mounting member 28 ... Vibration isolation substrate 28a ... Vibration isolation substrate portion 32 ... Flange portion 34 ... Through hole 46 ... Shaft member 46a ... Lower end of shaft member 48 ... Stator 62 ... Housing member 68 DESCRIPTION OF SYMBOLS ... Top plate part, 72 ... Recessed part, 74 ... Prone saddle member, 82 ... Vibration sensor (vibration detection means), 84 ... Axle part (wheel side member), 100 ... Excitation apparatus, 120 ... Excitation apparatus, 122 ... mass body, 124 ... rubber-like elastic body, 130 ... vibration device, 132 ... rubber-like elastic body, 140 ... vibration device, 142 ... cylindrical portion, 144 ... vibration plate, X ... axial direction

Claims (8)

An anti-vibration device comprising an anti-vibration base made of a rubber-like elastic body that is interposed between the wheel-side member and the vehicle body and connects the wheel-side member and the vehicle body;
Vibration detecting means attached to the wheel side member for detecting vibration in the predetermined frequency range of the wheel side member;
A vibration device attached to the vehicle body and capable of vibrating the vehicle body;
With
Drive control of the vibration exciter based on the signal from the vibration detection means, and by vibrating the vehicle body, the air in the vehicle interior is vibrated to reduce the sound in the vehicle interior.
Noise reduction system. The vibration device includes a shaft member as a mover, a stator that is provided on an outer peripheral side of the shaft member and supports the shaft member so as to reciprocate in the axial direction, and the stator is accommodated and held inside. A cylindrical housing member,
The front end portion of the shaft member is fixed to the vehicle body, and the housing member is fixed to the vehicle body on the outer peripheral side of the fixed portion of the shaft member with respect to the vehicle body.
The noise reduction system according to claim 1. The housing member has a lower end fixed to the upper surface of the vehicle body, an upper end opening is closed by the top plate, and the stator is suspended from the top plate.
The shaft member has a lower end fixed to the vehicle body inside the housing member.
The noise reduction system according to claim 2. The vibration isolator is a suspension support interposed between a shock absorber rod and a vehicle body,
A through hole through which the upper end of the rod is inserted is provided in the vehicle body;
A prominent saddle-like member that forms a downwardly opened recess that accommodates the upper end of the rod inserted through the through hole is attached to the vehicle body so as to close the through hole,
The lower end portion of the shaft member is fixed to the ceiling surface of the face-down saddle member,
The noise reduction system according to claim 3. The vibration device includes a shaft member as a mover, a stator that is provided on an outer peripheral side of the shaft member and supports the shaft member so as to reciprocate in the axial direction, and the stator is accommodated and held inside. A cylindrical housing member,
The housing member is fixed to the vehicle body, and a mass body is attached to a distal end portion of the shaft member inside the housing member, and the vehicle body is vibrated by exciting the mass body. The noise reduction system according to claim 1 configured. The housing member has a lower end fixed to the upper surface of the vehicle body, an upper end opening is closed by the top plate, and the stator is suspended from the top plate.
The noise reduction system according to claim 5, wherein the mass body is coupled to the vehicle body via a rubber-like elastic body inside a fixing portion of the housing member with respect to the vehicle body. The housing member has a lower end fixed to the upper surface of the vehicle body, an upper end opening is closed by the top plate, and the stator is suspended from the top plate.
The mass body is coupled to the inner peripheral surface of the housing member via a rubber-like elastic body.
The noise reduction system according to claim 5. The vibration isolator is a suspension support interposed between a rod of a shock absorber and a vehicle body, and the suspension support is a cylindrical inner attachment member attached to an upper end portion of the rod; and the inner attachment member An outer mounting member that is attached to the vehicle body side, and the anti-vibration base that connects the inner mounting member and the outer mounting member,
The inner mounting member includes a flange portion that protrudes radially outward and is embedded in the vibration isolation base,
The vibration device includes a shaft member as a mover, and a stator that is provided on an outer peripheral portion of the shaft member and supports the shaft member so as to reciprocate in the axial direction.
A cylindrical portion surrounding the upper end portion of the inner mounting member is connected to the lower end portion of the shaft member, and a flange-like vibration plate that projects radially outward from the lower end portion of the cylindrical portion is located above the flange portion. The vibration plate is embedded in the vibration isolation base, and a vibration isolation base portion is interposed between the lower surface of the vibration plate and the upper surface of the flange portion.
The noise reduction system according to claim 1.

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