JP2013043515A - Tire road noise reduction apparatus and tire road noise evaluation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire road noise reduction apparatus which accurately detects tire road noise and appropriately reduces it, and to provide a tire road noise evaluation method for appropriately evaluating the tire road noise.SOLUTION: The tire road noise reduction apparatus includes: a wheel vibration measurement device 13 for measuring vibration of a wheel 12 on which a tire 11 is mounted; a cancellation vibration generating device 14 for generating cancellation vibration for canceling the wheel vibration measured by the wheel vibration measurement device 13; and a cancellation vibration output device 15 for outputting cancellation vibration generated by the cancellation vibration generation device 14.

Description

  The present invention relates to a tire road noise reduction device that reduces road noise generated from tires during traveling of a vehicle, and to a tire road noise evaluation method that evaluates this road noise.

  While the vehicle is running, tire road noise (tire cavity resonance noise) is generated. This road noise is caused by the vibration of the tire caused by road surface unevenness and the like being transmitted to the suspension, the body, and the like, and propagating as noise into the vehicle interior.

  As what reduces the tire cavity resonance sound as this tire road noise, there exists a thing described in the following patent document 1, for example. The tire cavity resonance reduction device described in Patent Document 1 collects sound in the tire air chamber with a microphone, and performs FFT analysis on the collected sound to determine the frequency and intensity of the sound that causes cavity resonance. Generates data to synthesize sound of the same intensity at the same frequency as the obtained frequency, adjusts the phase when outputting the sound based on the generated data to make a cancellation sound, and this phase-adjusted cancellation sound Is output from the loudspeaker to reduce tire cavity resonance noise.

JP 2006-064822 A

  In the tire cavity resonance sound reducing device of Patent Document 1 described above, the sound in the tire air chamber is collected by a microphone, and the frequency and intensity of the sound causing the cavity resonance are obtained based on the collected sound, and the phase The tire cavity resonance noise is reduced by outputting the canceling sound adjusted for the noise from the speaker. In this case, since the microphone is mounted in the wheel, the microphone collects not only the tire cavity resonance sound but also the sound of the surrounding environment.

  In other words, the noise is transmitted from the wheel to the suspension and body, and finally the vehicle interior panel vibrates to produce solid sound (indirect sound) and the sound emitted from the tire is external air. It can be distinguished from the air propagation sound (direct sound) that is transmitted to the vehicle and heard in the passenger compartment. In this case, the solid propagation sound is road noise or the like, and the air propagation sound is pattern noise or the like.

  In the tire cavity resonance reduction device of Patent Document 1, there is a possibility that the microphone collects not only road noise but also pattern noise. In addition, the microphone may collect not only tire noise but also sounds generated from the surrounding environment, such as traveling sound of other people and speaker noise. Then, this tire cavity resonance sound reducing device cannot collect proper cavity resonance sound (road noise) with a microphone, and cannot output a canceling sound that cancels the cavity resonance sound. The cavity resonance sound (road noise) cannot be reduced.

  The present invention solves the above-described problems, and detects a tire road noise with high accuracy and appropriately reduces the tire road noise, and appropriately evaluates the tire road noise. An object of the present invention is to provide a tire road noise evaluation method capable of

  In order to solve the above-described problems and achieve the object, the tire road noise reduction device of the present invention is a tire road noise reduction device that reduces the road noise by outputting a vibration that cancels the road noise generated by the tire. A wheel vibration measuring device that measures vibration of a wheel on which a tire is mounted, a canceling vibration generating device that generates a canceling vibration that cancels the wheel vibration measured by the wheel vibration measuring device, and the canceling vibration generating device. And a cancellation vibration output device that outputs the generated cancellation vibration.

  According to the tire road noise reduction device, the wheel vibration measuring device measures the wheel vibration, the canceling vibration generating device generates a canceling vibration that cancels the measured wheel vibration, and the canceling vibration output device generates the generated vibration. Output the canceling vibration. That is, tire road noise is detected as wheel vibration, and canceling vibration for canceling the wheel vibration is output, so that tire road noise can be detected with high accuracy and appropriately reduced.

  In the tire road noise reduction device according to the present invention, the wheel vibration measuring device includes a vibration sensor that measures vibration of the wheel.

  According to the tire road noise reduction device, the structure can be simplified by using the wheel vibration measuring device as a vibration sensor.

  In the tire road noise reduction device of the present invention, the wheel vibration measuring device measures vibrations in the circumferential direction of the wheel.

  According to this tire road noise reducing device, the wheel vibration measuring device measures the vibration in the circumferential direction of the wheel, thereby detecting the circumferential deformation in the wheel and causing a tire road noise in the tire cavity. Resonance sound can be detected appropriately.

  In the tire road noise reduction device according to the present invention, the wheel vibration measuring device includes a strain gauge attached to the wheel.

  According to the tire road noise reduction device, the wheel vibration measuring device can be a strain gauge, so that the structure can be simplified and the cost can be reduced, and the mounting property to the wheel can be improved. .

  In the tire road noise reduction device according to the present invention, the wheel vibration measuring device includes a piezoelectric element attached to the wheel.

  According to the tire road noise reduction device, the structure of the wheel vibration measuring device can be simplified and the cost can be reduced and the mounting property to the wheel can be improved by using the piezoelectric device as the wheel vibration measuring device. .

  Further, in the tire road noise reduction device of the present invention, the canceling vibration generating device can generate a canceling vibration by adjusting a phase by an operating device with respect to a frequency of the wheel vibration measured by the wheel vibration measuring device. A phase adjustment device and a radio wave reception device capable of receiving the cancellation vibration generated by the phase adjustment device by radio waves.

  According to this tire road noise reducing device, the phase adjusting device adjusts the phase with respect to the frequency of the wheel vibration by the operating device to generate the canceling vibration, and the radio wave receiving device converts the generated canceling vibration to the radio wave. Therefore, it is possible for the occupant to adjust the vibration phase using the operating device to generate the optimum canceling vibration, and to effectively reduce the tire road noise.

  The tire road noise evaluation method of the present invention is characterized by measuring the vibration of a wheel on which a tire is mounted and evaluating the road noise based on the measured wheel vibration.

  According to this tire road noise evaluation method, since the wheel vibration correlated with the tire road noise is detected, the road noise can be properly evaluated based on the wheel vibration.

  The tire road noise reduction device of the present invention measures wheel vibration, generates and outputs a cancellation vibration that cancels the measured wheel vibration, and thus detects tire road noise with high accuracy and appropriately reduces this. be able to.

  Since the tire road noise evaluation method according to the present invention evaluates road noise based on wheel vibration, the tire road noise can be properly evaluated.

FIG. 1 is a principle diagram of a tire road noise reduction device according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram of the tire road noise reduction device according to the first embodiment. FIG. 3 is a flowchart showing the operation of the tire road noise reduction device according to the first embodiment. FIG. 4 is a graph showing wheel vibration measured by a strain gauge. FIG. 5 shows FFT analysis data of wheel vibration. FIG. 6 is a graph showing the canceling vibration with respect to the wheel vibration. FIG. 7 is a graph showing the sound pressure measured by the sound pressure meter. FIG. 8 is a principle diagram of a tire road noise reduction device according to the second embodiment of the present invention. FIG. 9 is a schematic configuration diagram of the tire road noise reduction device according to the second embodiment. FIG. 10 is a schematic configuration diagram of a tire road noise reduction device according to a third embodiment of the present invention.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. The constituent elements of this embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same. Further, the plurality of embodiments described in this embodiment can be arbitrarily combined within the scope obvious to those skilled in the art.

[First Embodiment]
FIG. 1 is a principle diagram of a tire road noise reduction device according to the first embodiment of the present invention, FIG. 2 is a schematic configuration diagram of the tire road noise reduction device of the first embodiment, and FIG. 3 is a diagram of the first embodiment. FIG. 4 is a graph showing the wheel vibration measured by the strain gauge, FIG. 5 is an FFT analysis data of the wheel vibration, and FIG. 6 is a graph showing the canceling vibration with respect to the wheel vibration. FIG. 7 is a graph showing the sound pressure measured by the sound pressure meter.

  As shown in FIG. 1, the tire road noise reduction device of the first embodiment reduces the road noise by outputting a vibration that cancels the road noise generated by the tire 11. The tire road noise reduction device includes a wheel vibration measurement device 13 that measures vibration of a wheel 12 on which a tire 11 is mounted, and a cancellation vibration generation that generates a cancellation vibration that cancels the wheel vibration measured by the wheel vibration measurement device 13. The apparatus 14 includes a cancellation vibration output apparatus 15 that outputs the cancellation vibration generated by the cancellation vibration generation apparatus 14.

  The canceling vibration generating device 14 analyzes the vibration of the wheel 12 measured by the wheel vibration measuring device 13 and obtains a peak frequency (frequency of vibration that causes road noise) and its magnitude (intensity). Generate data for synthesizing vibrations of the same frequency and the same magnitude as this frequency, and adjust the phase when outputting sound based on the generated data to make a cancellation sound (cancellation vibration) The canceling vibration output device 15 outputs the canceling sound adjusted in phase.

  The tire road noise reduction device of the first embodiment is mounted on a wheel 12 on which a tire 11 is mounted, as shown in FIG. The wheel vibration measuring device 13 is a vibration sensor that measures vibrations in the circumferential direction of the wheel 12, and is specifically a strain gauge attached to the wheel 12. That is, the strain gauge as the wheel vibration measuring device 13 can detect a minute change (strain) in the circumferential direction of the wheel 12 as an electric signal. The wheel vibration measuring device 13 is not limited to this configuration, and may be a piezoelectric element (such as a piezoelectric film or a piezoelectric cable) attached to the wheel 12.

  The cancellation vibration generating device 14 converts the wheel vibration measured by the wheel vibration measuring device 13 into a digital signal from an analog signal by the AD converter 21 and inputs it as vibration data. The canceling vibration generating device 14 generates canceling vibration that cancels the wheel vibration, converts the digital signal from the digital signal into an analog signal, and outputs the analog signal to the canceling vibration output device 15 as vibration data. The canceling vibration output device 15 is a vibrator and outputs canceling vibration as vibration data generated by the canceling vibration generating device 14 to the wheel 12.

  More specifically, the cancellation vibration generation device 14 includes an input interface 31, a data storage device 32, a dynamic strain meter 33, an FFT (Fast Fourier Transform) analysis device 34, a synthetic vibration data generation device 35, a phase adjustment device 36, An output interface 37 is included.

  The data storage device 32 stores vibration data measured by the wheel vibration measuring device 13 and converted into a digital signal by the AD converter 21. In this case, the data storage device 32 can store the number of data necessary for the FFT analysis by the FFT analysis device 34 so as to be first-in first-out. The dynamic strain meter 33 reads vibration data stored in the data storage device 32, amplifies the read vibration data, and outputs it as a voltage (current).

  The FFT analyzer 34 performs processing (frequency analysis) for extracting which frequency component is included in the vibration data amplified by the dynamic strain meter 33. Then, the FFT analysis device 34 performs processing for obtaining the frequency and magnitude (intensity) of the vibration that causes tire road noise in a predetermined frequency region (230 Hz to 250 Hz) among the analyzed frequency components. Do.

  The synthetic vibration data generation device 35 is a vibration required to output the vibration having the same frequency as the vibration frequency causing the tire road noise generated by the FFT analysis device 34 in the same magnitude as that obtained. Data (synthetic vibration data) is generated. The combined vibration data generation device 35 generates combined vibration data of two frequencies (for example, combined vibration data of 230 Hz and 240 Hz). In this case, if there is only one vibration frequency peak that causes the tire road noise determined by the FFT analyzer 34, the combined vibration data generator 35 may generate vibration data of one frequency (for example, 230 Hz). Vibration data), and if there are three or more vibration frequency peaks that cause the tire road noise determined by the FFT analyzer 34, the combined vibration data generator 35 has three or more frequencies. Synthesize vibration data and output.

  When the phase adjustment device 36 outputs this vibration based on the combined vibration data generated by the combined vibration data generation device 35, the phase adjustment device 36 adjusts the phase of the vibration so that the output vibration becomes a canceling vibration. The phase of the vibration is adjusted. That is, the phase adjusting device 36 outputs vibration data having an opposite phase to the combined vibration data generated by the combined vibration data generating device 35. The method of adjusting the phase of vibration by the phase adjustment device 36 is realized, for example, by temporarily storing the combined vibration data in the storage device and outputting the stored combined vibration data with a delay time. Can do.

  Here, operation | movement of the tire road noise reduction apparatus of 1st Embodiment is demonstrated based on the flowchart of FIG.

  In the operation of the tire road noise reduction device according to the first embodiment, as shown in FIG. 3, in step S <b> 11, the strain gauge as the wheel vibration measuring device 13 measures the vibration (distortion amount) in the circumferential direction of the wheel 12. To do. In step S12, the AD converter 21 converts the wheel vibration measured by the wheel vibration measuring device 13 from an analog signal to a digital signal.

  In the canceling vibration generating device 14, the input interface 31 inputs the vibration data converted into a digital signal, and in step S13, the data storage device 32 stores the vibration data. In step S14, the dynamic strain meter 33 reads the vibration data stored in the data storage device 32 and amplifies the read vibration data.

  In step S <b> 15, the FFT analysis device 34 performs frequency analysis to extract which frequency components are included in the vibration data amplified by the dynamic strain meter 33. That is, the FFT analyzer 34 performs a process of obtaining a frequency and a magnitude (intensity) of a vibration that causes tire road noise in a predetermined frequency region (230 Hz to 250 Hz) by performing frequency analysis. In this case, the FFT analyzer 34 can appropriately deal with dynamically changing tire road noise by continuously processing repeated vibration data that is sequentially transmitted.

  In step S <b> 16, the combined vibration data generation device 35 generates vibrations having the same frequency and the same magnitude as the vibration frequencies that cause the tire road noise generated by the FFT analysis device 34, for example, 230 Hz and 240 Hz. Synthetic vibration data for generating In step S17, the phase adjusting device 36 adjusts the phase of the vibration so that the vibration output by adjusting the phase of the vibration becomes a canceling vibration when outputting the vibration based on the combined vibration data. adjust.

  The vibration phase adjustment is performed, for example, when the vibration intensity analyzed by the FFT analyzer 34 is larger than a preset threshold or when the vibration intensity is at a level higher than a predetermined time. Otherwise, the phase adjustment device 36 does not need to perform phase adjustment.

  The generated cancellation vibration data is output via the output interface 37, and in step S18, the DA converter 22 converts the digital signal into an analog signal. In step S <b> 19, the vibration exciter as the cancellation vibration output device 15 outputs the cancellation vibration generated by the cancellation vibration generation device 14 to the wheel 12. That is, the canceling vibration output device 15 applies vibrations that have peaks at two frequencies (230 Hz and 240 Hz) in the wheel vibration to the wheel 12, so that the wheel vibration and the canceling vibration weaken each other, and road noise Reduce.

  More specifically, the strain gauge as the wheel vibration measuring device 13 measures the wheel vibration in the circumferential direction of the wheel 12 as shown in FIG. In this case, time T is the waveform of one rotation of the tire 11 (wheel 12). The FFT analyzer 34 can obtain a frequency characteristic of road noise as shown in FIG. 5 by performing frequency analysis on the measured wheel vibration. In this case, in the region A, since it peaks at two high frequencies 230 Hz and 240 Hz, it can be seen that the vibrations of these two high frequencies 230 Hz and 240 Hz cause road noise.

As a result, the phase adjuster 36, as shown in FIG. 6, with respect to the wheel vibrations V _1, to produce a cancellation vibration V _2. Cancel vibration output device 15, with respect to the wheel vibrations V _1, cancel each other out by outputting the canceling vibration V ₂ opposite phases, wheel vibrations V _1, that is, road noise is reduced.

  In this embodiment, road noise is evaluated as vibration of the wheel 12 (wheel vibration). That is, when road noise is collected as sound by a microphone and frequency analysis is performed, the frequency characteristics of road noise can be obtained as shown in FIG. From the frequency characteristics of this road noise, it can be seen that in region B, peaks are observed at two high frequencies 230 Hz and 240 Hz. In this case, comparing the frequency characteristic obtained by frequency analysis of the wheel vibration (FIG. 5) and the frequency characteristic obtained by frequency analysis of the road noise (FIG. 7), both are high in each region A and B. It has peaks at frequencies of 230 Hz and 240 Hz. From this, it can be understood that there is a correlation between road noise (sound) and wheel vibration. That is, by evaluating wheel vibration as road noise, it can be applied not only to the above-described road noise reduction, but also to, for example, analysis of the cause of road noise generation and tire and wheel design.

  Thus, in the road noise reduction device according to the first embodiment, the wheel vibration measuring device 13 that measures the vibration of the wheel 12 on which the tire 11 is mounted, and the wheel vibration measured by the wheel vibration measuring device 13 are canceled out. A canceling vibration generating device 14 that generates a canceling vibration and a canceling vibration output device 15 that outputs the canceling vibration generated by the canceling vibration generating device 14 are provided.

  Therefore, the wheel vibration measuring device 13 measures the vibration of the wheel 12, the canceling vibration generating device 14 generates a canceling vibration that cancels the measured wheel vibration, and the canceling vibration output device 15 generates the canceling vibration. Is output. That is, the tire road noise is detected as the vibration of the wheel 12, and the canceling vibration for canceling the wheel vibration is output. Therefore, the tire road noise can be detected with high accuracy and appropriately reduced.

  Further, in the road noise reduction device of the first embodiment, the wheel vibration measuring device 13 is a vibration sensor that measures the vibration of the wheel 12, so that the structure can be simplified.

  Further, in the road noise reduction device of the first embodiment, the wheel vibration measuring device 13 measures the vibration in the circumferential direction of the wheel 12, and therefore, the deformation in the circumferential direction of the wheel 12 is detected to cause tire road noise. The cavity resonance sound in the tire 11 can be detected appropriately.

  In the road noise reduction device according to the first embodiment, since the wheel vibration measuring device 13 is a strain gauge attached to the wheel 12, the structure can be simplified and the cost can be reduced. Wearability to the can be improved.

  Further, in the road noise reduction device of the first embodiment, since the wheel vibration measuring device is a piezoelectric element attached to the wheel 12, the structure can be simplified and the cost can be reduced, and Wearability can be improved.

  In the tire road noise evaluation method according to the first embodiment, the vibration of the wheel 12 on which the tire 11 is mounted is measured, and the road noise is evaluated based on the measured vibration of the wheel 12. Therefore, since the vibration of the wheel 12 that is correlated with the tire road noise is detected, the road noise can be appropriately evaluated based on the vibration of the wheel 12.

[Second Embodiment]
FIG. 8 is a principle diagram of a tire road noise reduction device according to the second embodiment of the present invention, and FIG. 9 is a schematic configuration diagram of the tire road noise reduction device of the second embodiment. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  As shown in FIG. 8, the tire road noise reduction device according to the second embodiment reduces the road noise by outputting a vibration that cancels the road noise generated by the tire 11. The tire road noise reduction device includes a wheel vibration measurement device 13 that measures vibration of a wheel 12 on which a tire 11 is mounted, and a cancellation vibration generation that generates a cancellation vibration that cancels the wheel vibration measured by the wheel vibration measurement device 13. The apparatus 14 includes a cancellation vibration output apparatus 16 that outputs the cancellation vibration generated by the cancellation vibration generation apparatus 14.

  The canceling vibration generating device 14 analyzes the vibration of the wheel 12 measured by the wheel vibration measuring device 13 and obtains a peak frequency (frequency of vibration that causes road noise) and its magnitude (intensity). Generate data for synthesizing vibrations with the same frequency and the same magnitude as this frequency, and adjust the phase when sound is output based on the generated data. The cancellation vibration output device 15 outputs the phase-adjusted cancellation sound.

  As shown in FIG. 9, the tire road noise reduction device of the second embodiment is mounted on a wheel 12 on which a tire 11 is mounted. The wheel vibration measuring device 13 is a vibration sensor that measures vibrations in the circumferential direction of the wheel 12, and is specifically a strain gauge attached to the wheel 12. The canceling vibration generating device 14 inputs the wheel vibration measured by the wheel vibration measuring device 13 as a digital signal by the AD converter 21 and generates a canceling vibration for canceling the wheel vibration, and then the analog signal is output by the DA converter 22. And output to the cancellation vibration output device 16 as vibration data. The canceling vibration output device 16 is a speaker, and outputs canceling vibration as vibration data generated by the canceling vibration generating device 14 into the air.

  Specifically, the canceling vibration generating device 14 includes an input interface 31, a data storage device 32, a dynamic strain meter 33, an FFT analyzing device 34, a synthetic vibration data generating device 35, a phase adjusting device 36, and an output interface 37. Has been.

  The data storage device 32 stores vibration data measured by the wheel vibration measuring device 13 and converted into a digital signal by the AD converter 21. The FFT analyzer 34 performs frequency analysis on the vibration data amplified by the dynamic strain meter 33, and the vibration frequency that causes tire road noise in a predetermined frequency region (230 Hz to 250 Hz) among the analyzed frequency components. And its size (strength). The composite vibration data generation device 35 generates vibration data (synthetic vibration data) necessary for outputting the vibration having the same frequency as the frequency of the vibration that causes the tire road noise in the same magnitude. Generate. When the vibration is output based on the combined vibration data, the phase adjustment device 36 adjusts the phase of the vibration so that the vibration to be output becomes a cancellation vibration by adjusting the phase of the vibration.

  In this case, when the phase adjustment device 36 generates the canceling vibration, the canceling vibration generating device 14 outputs a canceling vibration waveform, so that the canceling vibration output device 16 responds to the canceling vibration waveform. The sound is output from the speaker. Note that the canceling vibration output device 16 may output sound around the tire 11 and the wheel 12 or may output the sound into the passenger compartment.

  As described above, in the road noise reduction device according to the second embodiment, the wheel vibration measuring device 13 that measures the vibration of the wheel 12 on which the tire 11 is mounted, and the wheel vibration measured by the wheel vibration measuring device 13 are canceled out. A canceling vibration generating device 14 that generates a canceling vibration and a canceling vibration output device 16 that outputs the canceling vibration generated by the canceling vibration generating device 14 are provided.

  Therefore, the wheel vibration measuring device 13 measures the vibration of the wheel 12, the canceling vibration generating device 14 generates a canceling vibration that cancels the measured wheel vibration, and the canceling vibration output device 16 generates the canceling vibration. As a sound. That is, the tire road noise is detected as the vibration of the wheel 12, and a canceling sound for canceling the wheel vibration is output. Therefore, the tire road noise can be detected with high accuracy and appropriately reduced.

[Third Embodiment]
FIG. 10 is a schematic configuration diagram of a tire road noise reduction device according to a third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  As shown in FIG. 10, the tire road noise reduction device according to the third embodiment includes a wheel vibration measuring device 13 that measures the vibration of the wheel 12 on which the tire 11 is mounted, and the wheel vibration measured by the wheel vibration measuring device 13. The canceling vibration generating device 14 generates a canceling vibration to cancel, and the canceling vibration output device 15 outputs the canceling vibration generated by the canceling vibration generating device 14.

  The wheel vibration measuring device 13 is a strain gauge that measures vibration in the circumferential direction of the wheel 12, and is connected to the canceling vibration generating device 14 via the AD converter 21. The canceling vibration generation device 14 includes an input interface 31, a data storage device 32, a dynamic strain meter 33, an FFT analysis device 34, a combined vibration data generation device 35, a phase adjustment device (first phase adjustment device) 36, and an output interface 37. It is configured. The canceling vibration generating device 14 outputs canceling vibration that cancels the wheel vibration, and is connected to the canceling vibration output device 15 via the DA converter 22. The cancellation vibration output device 15 is a vibration exciter and outputs a cancellation vibration as vibration data generated by the cancellation vibration generation device 14 to the wheel 12.

  The canceling vibration generating device 14 includes a second phase adjusting device capable of generating a canceling vibration by adjusting the phase with respect to the frequency of the wheel vibration measured by the wheel vibration measuring device 13 by the operation device, and a second phase. It has a radio wave receiving device capable of receiving the canceling vibration generated by the adjusting device by radio waves.

  In other words, the receiver 41 is connected to the input interface 31 of the canceling vibration generating apparatus 14, and the receiver 41 has an antenna 42. The receiver 41 can output the received signal to the phase adjustment device 36. The output interface 37 is connected to a transmitter 43, and the transmitter 43 has an antenna 44. The transmitter 43 can transmit vibration data subjected to frequency analysis by the FFT analyzer 34 as a signal.

  The processing device 51 as the second phase adjusting device is connected to a receiver 52, and the receiver 52 has an antenna 53. The receiver 52 can receive a signal transmitted from the transmitter 43, that is, vibration data subjected to frequency analysis by the FFT analyzer 34 as a signal, and can output the signal to the processing device 51. The processing device 51 is connected to a transmitter 54, and the transmitter 54 has an antenna 55. The transmitter 54 can transmit the cancellation vibration data processed by the processing device 51 as a signal. The receiver 41 receives the cancellation vibration data transmitted from the transmitter 54 as a signal and outputs the signal to the phase adjustment device 36.

  The processing device 51 is connected to a keyboard 56 as an operation device and a display device 57. In this case, the processing device 51, the keyboard 56, the display device 57, and the like are configured as an in-vehicle unit that transmits a manual phase adjustment signal for manually adjusting the phase of the canceling vibration to the canceling vibration generating device 14.

  Therefore, the strain gauge as the wheel vibration measuring device 13 measures the vibration in the circumferential direction of the wheel 12, and the measured wheel vibration is input to the canceling vibration generating device 14 via the AD converter 21. Here, in the cancellation vibration generating device 14, the data storage device 32 stores the vibration data, the dynamic strain meter 33 amplifies the vibration data, and the FFT analysis device 34 performs frequency analysis of the vibration data. That is, the FFT analyzer 34 performs a process of obtaining a frequency and a magnitude (intensity) of a vibration that causes tire road noise in a predetermined frequency region (230 Hz to 250 Hz) by performing frequency analysis.

  The vibration data analyzed by the FFT analysis device 34 is transmitted as a vibration data signal by the transmitter 43, and the receiver 52 receives this signal and outputs it to the processing device 51. Based on the input signal, the processing device 51 determines the frequency analysis result of the FFT analysis device 34, that is, the frequency and magnitude of vibration that causes tire road noise in a predetermined frequency region (230 Hz to 250 Hz). (Intensity) is displayed on the display device 57. Therefore, the occupant can recognize the occurrence state of tire road noise from the data displayed by the display device 57. The display device 57 visually displays the occurrence state of tire road noise in one of all four tires 11 (wheels 12) or in all the tires 11 (wheels 12).

  Since the occupant can recognize the occurrence state of the tire road noise by the display device 57, the occupant operates the keyboard 56 to instruct to cancel the phase of vibration for each tire 11 (wheel 12) (frequency and phase adjustment amount). Enter the key. That is, the occupant generates a manual phase adjustment signal for each tire 11 (wheel 12) by the processing device 51, and transmits instruction data for canceling vibration phase adjustment by the transmitter. Then, the receiver 41 receives the cancellation vibration phase adjustment instruction data transmitted by the transmitter 54 and outputs the received instruction data to the phase adjustment device 36.

  The canceling vibration generating device 14 generates combined vibration data for generating vibrations having the same frequency and the same magnitude as those of the vibration that causes the combined vibration data generating device 15 to generate tire road noise, for example, 230 Hz and 240 Hz. Generate. The phase adjustment device 36 generates a cancellation vibration based on the combined vibration data and the instruction data for the phase adjustment of the cancellation vibration sent from the processing device 51.

  The generated cancellation vibration is output to the cancellation vibration output device 15, and the cancellation vibration output device 15 outputs the generated cancellation vibration to the wheel 12. That is, the canceling vibration output device 15 applies vibrations that have peaks at two frequencies (230 Hz and 240 Hz) in the wheel vibration to the wheel 12, so that the wheel vibration and the canceling vibration weaken each other, and road noise Reduce.

  As described above, in the road noise reduction device according to the third embodiment, the wheel vibration measuring device 13, the canceling vibration generating device 14, and the canceling vibration output device 15 are provided, and the canceling vibration generating device 15 is configured as a wheel vibration. The processing device 51 capable of generating a canceling vibration by adjusting the phase with the keyboard 56 with respect to the frequency of the wheel vibration measured by the measuring device 13, and the wireless capable of transmitting and receiving the canceling vibration generated by the processing device 51 by radio waves. Wave transceivers 41, 43, 52, 54 are provided.

  Therefore, the wheel vibration measuring device 13 measures the vibration of the wheel 12, the canceling vibration generating device 14 generates a canceling vibration that cancels the measured wheel vibration, and the canceling vibration output device 15 generates the canceling vibration. Is output. That is, the tire road noise is detected as the vibration of the wheel 12, and the canceling vibration for canceling the wheel vibration is output. Therefore, the tire road noise can be detected with high accuracy and appropriately reduced.

  At this time, the processing device 51 adjusts the phase according to the input instruction from the keyboard 56 with respect to the frequency of the wheel vibration received from the canceling vibration generating device 14, and cancels out the phase adjustment instruction data. Send to. Then, the cancellation vibration generator 14 generates a cancellation vibration based on the combined vibration data and the instruction data for phase adjustment of the cancellation vibration. Therefore, it becomes possible for the occupant to adjust the phase of the wheel vibration by manual operation to generate the optimum canceling vibration, and the tire road noise can be effectively reduced.

  In the first and third embodiments described above, the cancellation vibration output device 15 is configured to reduce the road noise by applying the cancellation vibration to the wheel 12, but the cancellation vibration is not limited to the wheel 12. You may give to an axle, a suspension, a body, etc.

DESCRIPTION OF SYMBOLS 11 Tire 12 Wheel 13 Wheel vibration measuring device 14 Cancellation vibration production | generation apparatus 15,16 Cancellation vibration output device 31 Input interface 32 Data storage device 33 Dynamic strain meter 34 FFT analysis device 35 Synthetic vibration data generation device 36 Phase adjustment device 37 Output Interface 41, 52 Receiver (Radio wave receiver)
43, 54 Transmitter (Radio wave receiver)
51 Processing device (phase adjusting device)
56 Keyboard 57 Display device

Claims (7)

In the tire road noise reduction device that reduces the road noise by outputting vibration that cancels road noise generated by the tire,
A wheel vibration measuring device for measuring the vibration of the wheel on which the tire is mounted;
A canceling vibration generating device for generating a canceling vibration for canceling the wheel vibration measured by the wheel vibration measuring device;
A cancellation vibration output device that outputs the cancellation vibration generated by the cancellation vibration generation device;
A tire road noise reduction device comprising:   The tire road noise reduction device according to claim 1, wherein the wheel vibration measurement device includes a vibration sensor that measures vibration of the wheel.   The tire road noise reduction device according to claim 1, wherein the wheel vibration measurement device measures vibrations in a circumferential direction of the wheel.   The tire road noise reduction device according to any one of claims 1 to 3, wherein the wheel vibration measurement device includes a strain gauge attached to the wheel.   The tire road noise reduction device according to any one of claims 1 to 3, wherein the wheel vibration measurement device includes a piezoelectric element attached to the wheel.   The canceling vibration generating device is generated by the phase adjusting device capable of generating a canceling vibration by adjusting a phase by an operation device with respect to a frequency of the wheel vibration measured by the wheel vibration measuring device. The tire road noise reduction device according to any one of claims 1 to 5, further comprising a radio wave receiving device capable of receiving the canceling vibration by radio waves. Measure the vibration of the wheel where the tire is mounted,
Evaluate road noise based on measured wheel vibration,
The tire road noise evaluation method characterized by the above-mentioned.

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