JPH0571578A - Suppressing device for vibration and noise for vehicle - Google Patents

Abstract

PURPOSE:To sufficiently reduce the vibration of a vehicle and prevent the deterioration of responsiveness. CONSTITUTION:The detection signal of a microphone 20 is divided into the primary component and secondary component of the engine explosion frequency by a band path filter 21. The primary component is outputted into the first vibrator control circuit 22, and the secondary component is outputted into the second vibrator control circuit 23. The first vibrator control circuit 22 vibrates the first vibrator 17 so as to reduce the primary component, and the second vibrator control circuit 23 vibrates the second vibrator 8 so as to reduce the secondary component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle vibration or noise reduction device.

[0002]

2. Description of the Related Art JP-A-61-218427 discloses
A vibration sensor that detects the vibration of the vehicle, a bandpass filter that separates and extracts the vibration of the vehicle for each vibration mode from the detection signal of this vibration sensor, and a component that cancels the component for each vibration mode of the vibration of the vehicle. Each control circuit that generates a control signal and an adder circuit that adds each output signal of each control circuit are provided, and the vehicle vibration is reduced by operating a single vibration exciter based on the output signal of the adder circuit. A vehicular vibration reduction device is disclosed which is adapted to be squeezed.

With this device, a plurality of different frequency components of vehicle vibration can be reduced.

[0004]

However, in this device, since the output signals of the control circuits are added by the adder circuit, there arises a problem that the control time becomes long and the responsiveness deteriorates.

[0005]

In order to solve the above problems, according to the present invention, a plurality of actuators are provided, and the actuators are operated to generate vibrations or noises having a phase substantially opposite to that of the vibrations or noises of the vehicle. A vehicle vibration or noise reduction device that is configured to reduce the vibration or noise of the vehicle at least includes a control unit that operates each actuator so as to reduce the vibration or noise of the vehicle having a different frequency.

[0006]

The actuators are operated so as to reduce the vibration or noise of the vehicle of different frequencies. Therefore, the vibration or noise of the vehicle can be sufficiently reduced without using an adding circuit.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an overall view of a vehicle noise reduction device for reducing muffled noise caused by vehicle vibration. Referring to FIG. 1, 10 is a vehicle and 1 is a radiator. 2 shows a front view of the radiator 1, and FIG. 3 shows a right side view of FIG. Referring to FIG. 2 and FIG. 3, the upper end of the radiator 1 has an upper support 3 via a support body 2 made of rubber.
The radiator 1 can be moved up and down. The lower end of the radiator 1 is supported by the first and second vibrators 7 and 8 at the left and right ends of the lower tank 4 at the lower end of the radiator 1 via arms 5 and 6, respectively.
The first and second vibrators 7 and 8 are front cross members 9
An internal combustion engine is mounted on a body frame (not shown) that is fixed to the top and is connected to the front cross member 9.

FIG. 4 shows an enlarged sectional view of the first vibration exciter 7. Referring to FIG. 4, the support piston 11 provided at the lower portion of the vibration exciter 7 is fixed to the front cross member 9. The support piston 11 is a cylindrical case 12 of the vibrator 7.
It is inserted into the inside from below, and a cylindrical nut 13 is screwed onto the lower end of the case 12. Support piston 11
Penetrates the nut 13. The case 12 and the nut 13 are slidably displaceable along the outer peripheral surface of the support piston 11, and a disc spring 14 is arranged between the support piston 11 and the nut 13, so that the case 12 and the nut 1 are provided.
3 is urged downward relative to the support piston 11. A piezoelectric element 15 is provided in the case 12.
The upper end of the piezoelectric element 15 is engaged with the upper bottom surface of the case 12, and the lower end of the piezoelectric element 15 is engaged with the upper end of the support piston 11. The outer circumference of the nut 13 is connected to the arm 5 via an annular rubber bush 16.

The piezoelectric element 15 expands and contracts according to the applied voltage. When the piezoelectric element 15 expands and contracts, the case 12 and the nut 13 are displaced relative to the support piston 11. Therefore, when the voltage applied to the piezoelectric element 15 is changed, the nut 13 can be vibrated relative to the support piston 11 according to the change in the voltage.
Therefore, a control voltage having a predetermined frequency, phase, and gain according to the engine speed is applied to the piezoelectric element 15 to vibrate the vibration exciter 7, thereby canceling the vibration generated in the vehicle. The radiator 1 can be vibrated as described above.

The second vibrator 8 also has the same structure as the first vibrator 7. FIG. 5 shows an example of a spectrum map of muffled noise caused by vehicle vibration. In this example, the engine explosion frequency primary and secondary components are particularly high. Therefore, in the present embodiment, the engine explosion frequency primary component and secondary component of muffled noise are reduced. Referring again to FIG. 1, a microphone 20 for detecting a muffled sound in the vehicle compartment is disposed in the front seat in the vehicle compartment. The detection signal of the microphone 20 is input to the bandpass filter 21. The bandpass filter 21 separates the primary component and the secondary component of the engine explosion frequency, outputs the signal of the primary component to the first exciter control circuit 22, and outputs the signal of the secondary component to the second exciter control. Output to the circuit 23.

The first vibration exciter control circuit 22 outputs the muffled noise 1
A sine wave having a frequency corresponding to the frequency of the next component is generated. The phase and amplitude of this sine wave are feedback-controlled so as to reduce the first-order component of muffled sound. That is, the phase and amplitude of the sine wave are feedback-controlled so as to have the opposite phase and the same amplitude as the phase of the primary component of the muffled sound. The first shaker 7 is controlled by the output signal of the first shaker control circuit 22. As a result, the engine explosion frequency primary component of muffled sound can be reduced.

The second vibrator 8 is also controlled by the second vibrator control circuit 23 in the same manner, whereby the engine explosion frequency secondary component of the muffled noise can be reduced. As described above, according to the present embodiment, it is possible to reduce the engine explosion frequency primary and secondary components of the muffled sound, and as a result, it is possible to sufficiently reduce the muffled sound.

Further, since the respective exciters 7 and 8 are driven by the sine wave signal and are not driven by the complicated output signal added by the adding circuit unlike the conventional device, the respective exciters 7 and 8 are complicated. There is no problem that durability does not work because it does not operate. Further, since the primary component and the secondary component of the engine explosion frequency can be reduced without using an adding circuit as in the conventional device, it is possible to prevent deterioration of responsiveness due to using the adding circuit.

Although a plurality of vibration exciters are used as actuators in the present embodiment, a plurality of speakers may be used to perform feedback control so as to generate a sound having an opposite phase and the same amplitude as the muffled sound. Further, instead of the microphone 20 of the present embodiment, for example, an acceleration sensor is provided in the steering wheel,
The vibration of the steering wheel during idling may be reduced. In this case, based on the first-order component and the second-order component of the acceleration detected by the acceleration sensor, the respective exciters 7 and 8 are feedback-controlled so as to generate vibrations having the opposite phase and the same amplitude. Be done. As a result, the vibration of the vehicle is sufficiently reduced.

Although the feedback control has been described in this embodiment, the signals of the primary component and the secondary component may be generated based on the engine speed and the control may be performed based on the map.

[0016]

The vibration or noise of the vehicle can be sufficiently reduced. In addition, it is possible to prevent the responsiveness from being deteriorated because an adding circuit as in the conventional device is unnecessary.

[Brief description of drawings]

FIG. 1 is an overall view of a vehicle noise reduction device.

FIG. 2 is a front view of a radiator.

FIG. 3 is a right side view of FIG.

FIG. 4 is an enlarged sectional view of a vibration exciter.

FIG. 5 is a spectrum map of muffled sound.

[Explanation of symbols]

 7 ... 1st vibrator 8 ... 2nd vibrator

Claims (1)

[Claims] 1. A vibration of a vehicle, comprising a plurality of actuators, wherein the actuators are actuated to generate vibrations or sounds of a phase substantially opposite to those of the vibrations or noises of the vehicle to reduce the vibrations or noises of the vehicle. In a noise reduction device, a vehicle vibration or noise reduction device comprising control means for operating each of the actuators so as to reduce vibration or noise of a vehicle having a different frequency.