Technical field
[0001]
The present invention relates to apparatus for evaluating abnormal sound detection method and steering system of the steering system.
BACKGROUND
[0002]
Final inspection of abnormal sound caused by the steering system, the running test of the vehicle, the abnormal noise test driver is due to the steering system is carried out by evaluating tame and other noise. However, the noise in the passenger compartment of the vehicle is dominant tire road noise and engine noise, since the S / N ratio of the abnormal noise due to the steering system is small, that discern abnormal noise caused by the steering system hearing the It is difficult in many cases.
　Further, to detect the sound installation and the microphone near the ear position of the test driver, even for evaluation on the basis of the sound signal, in reality the it is difficult to extract only the component of abnormal sound caused by the steering system there were.
[0003]
　Therefore, as a technique for detecting an abnormal sound caused by the steering system, repeatedly enter the vibrations to the gear meshing section, a microphone or acceleration attached to a lower portion of the abnormal noise caused by due to the rotation of the gear meshing portion the electric power steering device it is known to detect by the sensor (e.g., see Patent Document 1).
CITATION
Patent Document
[0004]
Patent Document 1: Japanese Patent No. 4382647 Publication
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　However, in the technique of Patent Document 1, does not necessarily coincide with the abnormal sound heard actually in the car and abnormal noise detected at the bottom of the electric steering system, the vehicle travels without a problem detected sound or vibration there have been cases where to fail the test. There is also the mounting space of the microphone or acceleration sensor can not be secured, it is difficult to evaluate the entire steering system with the assembled electric steering system in the vehicle.
[0006]
　An object of the present invention is to provide an evaluation apparatus of noise detection method and the steering system accurately detectable steering system unusual noise generated from the steering system to improve the S / N ratio.
Means for Solving the Problems
[0007]
　The present invention comprises the following configuration.
(1) having a column shaft for rotatably supporting the steering wheel, a abnormal sound detection method of the steering system for detecting abnormal noise from the steering system that steers the wheels in response to rotation of the column shaft,
　using a microphone which is arranged to face the column shaft end of the steering wheel side of the column shaft, the sound from the column shaft end measures,
　the steering system from the sound signal output from the microphone generating abnormal noise detection signal due to
abnormal sound detection method of the steering system.
(2) having a column shaft for rotatably supporting the steering wheel, an evaluation device of the steering system for detecting abnormal noise from the steering system that steers the wheels in response to rotation of the column shaft,
　the column a microphone is placed against the column shaft end of the steering wheel side of the shaft,
　and supporting the steering system, the gantry comprising a vibrator for applying vibration,
　the vibration in the frame by the vibrator while applying, using the microphone, the sound from the column shaft end measures, a detection device for generating an abnormal sound detection signal caused from a sound signal to be output to the steering system from the microphone
comprises evaluation device of the steering system.
Effect of the invention
[0008]
　According to the present invention can accurately detect the abnormal noise generated from the steering system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
The abnormal sound detection method of [1] The present invention is a perspective view of a steering system for detecting abnormal sound.
It is a schematic diagram of FIG. 2 a steering wheel and a detection device microphone is installed.
3 is an explanatory view showing details of the arrangement of the microphones.
FIG. 4 is an explanatory view showing an embodiment of noise detection of installed steering system in a vehicle.
[5] the arrangement of the column shaft and the microphone is an explanatory view schematically showing.
6 is an explanatory view showing an embodiment of detecting the steering system single allophone.
7 is a spectrogram of the detected sound signal in the first embodiment.
8 is a spectrogram of the detected speech signals in Comparative Example 1.
9 is a graph showing the average spectrum of Example 1 and Comparative Example 1.
The frequency spectrum of FIG. 10 the sound pressure of the first embodiment shown in FIG. 9 is a graph showing a spectrum when subjected to mask processing by the band-pass filter.
DESCRIPTION OF THE INVENTION
[0010]
　Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
　Figure 1 is a perspective view of a steering system for detecting abnormal noise by abnormal noise detection method of the present invention. Hereinafter, the traveling direction of the vehicle front, the traveling direction will be referred to the backward direction opposite to the rear.
[0011]
　Steering system 11 includes a steering wheel 13 is rotated operably supported on the rear end portion of the column shaft 15. Column shaft 15, a cylindrical steering column 17 in a state of being inserted in the axial direction, is rotatably supported by the steering column 17. Column shaft 15, its front end is connected to the rear end of the intermediate shaft 21 via a universal joint 19. The front end of the intermediate shaft 21 via another universal joint 23 is connected to the input shaft 27 of the steering gear unit 25. Steering gear unit 25 transmits rotation of the input shaft 27, a pair of left and right steering shaft 29 extending in the vehicle width direction is connected to the front wheels of the vehicle.
[0012]
　In this steering system 11, by the steering wheel 13 is rotated, the input shaft 27 is rotated via the column shaft 15 and the intermediate shaft 21. Then, the steering shaft 29 with the rotation of the input shaft 27 moves in the axial direction, the front wheels are steering angle is steered is given.
[0013]
　Figure 2 is a schematic configuration view of a steering wheel and the detection device microphone is installed. Abnormal sound detection method according to the present configuration, the microphone 31 detects the abnormal noise from the steering system by using the detection device 33.
[0014]
　Microphone 31 has a sound collecting portion 35 to the distal end, capture the sounds in this sound collector 35, and outputs a sound signal. As the microphone 31, for example, of various methods such as dynamic microphones and condenser microphones can be used.
[0015]
　Microphone 31 is disposed facing the steering wheel 13. At that time, the steering wheel 13, remove the accessory members such as an air back module from the wheel body, a state of exposing the ends 45 of the column shaft 15. Here is the end 54 indicates the case where the male screw portion as an example, may have a configuration in which components mounted on the end 45 is exposed.
[0016]
　Microphone 31 is disposed on the vehicle rear side of the column shaft 15, a sound collecting portion 35 of the microphone 31 is disposed in a position facing the end portion 45 of the column shaft 15.
[0017]
　Microphone 31 is connected to the detection device 33 via a signal cable 32. Detection device 33 includes a frequency analyzer 37, a rattle sound component extraction unit 39, an evaluation unit 41. Although will be described in detail later in the processing contents of the detection device 33, the frequency analyzing unit 37 performs frequency analysis based on the sound signal outputted from the microphone 31. Rattle sound component extraction unit 39, from the frequency analysis result by the frequency analysis unit 37, extracts a rattling noise components each component constituting the steering system 11 is due to collisions when the relative displacement. Evaluation unit 41 obtains an evaluation value on the basis of the rattling noise component rattle component extractor 39 extracts, to evaluate the abnormal sound of the steering system 11.
[0018]
　Figure 3 is an explanatory view showing details of the arrangement of the microphone 31.
　The distance L between the end portion 45 and a microphone 31 of the column shaft 15, and 50mm or less. Incidentally, the microphone 31 is preferably placed close to the end 45 of the column shaft 15 so as not to interfere with the column shaft 15, and more preferably, 10mm or less the distance L.
[0019]
　Microphone 31 is preferably disposed on the axis X of the column shaft 15, the sound collector 35 if facing the end 45 of the column shaft 15, is inclined relative to the axis X of the column shaft 15 it may be. For example, depending on the directivity of the microphone 31, the inclination angle θ is ± 50 ° from the axis X of the column shaft 15, preferably may be in a range of ± 30 °.
[0020]
　Microphone 31 as described above, between the end 45 and the microphone 31 of the column shaft 15, is preferably placed in a state of a space S formed of only the air layer. That is, the microphone 31, the sound is not interrupted between the end 45 of the column shaft 15, or is placed in a state not blocked almost.
[0021]
　Next, a description will be given abnormal sound detection method for the above steering system 11.

　First, the steering system 11, mounted on a vehicle, illustrating a configuration for detecting the abnormal sound while being in a vehicle and integrally.
(Detection of noise)
　FIG. 4 is an explanatory view showing an embodiment of abnormal sound detection of installed steering system in a vehicle. In the illustrated example, in a state equipped with the steering system 11 on the vehicle V, while driving the vehicle V, to detect the abnormal noise from the steering system 11.
[0022]
　First, by operating the detection device 33 to drive the vehicle V. Road this time, for example, and cobbled road Belgian road and the like, cobblestone road or the like arranged embedded in a regular or irregular ground at a pitch of some 10 cm ~ 100 cm stone rounded, an uneven to run the R at a speed of 10km / h ~ 40km / h.
[0023]
　Then, during running of the vehicle V, to detect the sound emitted from the end 45 of the column shaft 15 with the microphone 31. Microphone 31 outputs to the detector 33 the detected sound as a sound signal.
[0024]
(Processing of noise signal)
　detecting device 33, the sound signal from the microphone 31, and input to the frequency analyzing unit 37 performs frequency analysis. Frequency analysis unit 37 obtains a frequency spectrum is the acoustic pressure distribution of each frequency of the sound signal, a frequency spectrum obtained is output to the rattle noise component extraction unit.
[0025]
　Rattle sound component extraction unit 39 extracts from the frequency spectrum output from the frequency analysis unit 37, a rattle noise component is abnormal noise signal due to the steering system 11. Specifically, rattling sound component extraction unit 39, from the input frequency spectrum, using a high pass filter, low-pass filter or band-pass filter, the sound of the band 300 Hz ~ 8 kHz in hearing that the rattle noise pressure strength selectively extracting, and its signal and abnormal sound signal. As the extraction frequency bands of rattling noise, the frequency band of 500 Hz ~ 5 kHz, more preferably to extract the acoustic pressure intensity of the frequency band.
[0026]
(Evaluation of abnormal noise signal)
　evaluation unit 41, the acoustic pressure of the resulting abnormal noise signal, for example, to determine whether or not it is within the allowable range set in advance, to evaluate the steering system 11.
[0027]
　According to abnormal sound detection method of the steering system according to the present method, the microphone 31 disposed in a position facing the end portion 45 of the column shaft 15 to detect the abnormal sound of the steering system 11. Steering system 11, because all the components are connected to the end 45 of the column shaft 15, the sound of the steering system 11 is emitted from the end 45 of the column shaft 15. By detecting the sound, you can accurately grasp the noise inside the steering system. Further, the end portion 45 of the column shaft 15 as a sound source, because the steering wheel 13 itself is to amplify the sound, by arranging the microphone 31 to the opposite position of the steering wheel 13, further improve the S / N ratio of the sound signal be able to.
[0028]
　Thus, upon actuation of the steering system 11, the rattling noise caused by the components with each other of the steering system 11 is in contact, it can be measured with high sensitivity from the microphone 31.
[0029]
　Further, the distance L between the end portion 45 and a microphone 31 of the column shaft 15 by a 50mm or less, can be measured abnormal sound of the steering system 11 with higher sensitivity.
[0030]
　Figure 5 is an explanatory view showing the positional relationship between the column shaft 15 and the microphone 31 schematically. As shown in the figure, between the end 45 and the microphone 31 of the column shaft 15 is in a space S formed of only the air layer. However, not limited to this, a portion of the space S, member 47 of lower sheet or cover or the like of non or shielding effect shielding the propagation of the sound may be located.
　For example, member 47 passes a specific frequency component including rattles, as long as it has the effect of blocking the other frequency components, simplifying the signal processing by the rattling noise component extraction unit 39, or may be omitted .
[0031]
　In this method, the sound measured by the microphone 31, to selectively extract the acoustic pressure intensity in the frequency band of 300 Hz ~ 8 kHz including a frequency band of the rattle noise caused by the steering system 11, more precisely the rattles It can be evaluated on. Thus, when detecting the abnormal sound by driving the vehicle V equipped with a steering system 11, the tire noise or the like while the vehicle is running, without being affected by other sounds ingredients, always stable and accurate allophone evaluation can be performed.
[0032]
　Further, the microphone 31, if it is arranged to face the end 45 of the column shaft 15, the support structure is not limited. Microphone 31 is preferably be integrally supported to the steering wheel 13, if thus supporting the microphone 31 to the steering wheel 13, the microphone 31 is unobtrusive to the operation of the steering wheel 13, the peripheral member it does not cause interference.
[0033]

　In the above example, measures the abnormal noise from the steering system 11 using only the microphone 31, it may be used in combination vibration sensor 43 for detecting vibration. In that case, as shown in FIG. 3, mounted on a position to be connected to the vibration sensor 43 to the column shaft 15 such as the end 45 of the column shaft 15 to detect the vibration of the column shaft 15 by the vibration sensor 43. Vibration sensor 43 outputs the detected vibration to the detection device 33 as a vibration detection signal. Detector 33 is evaluated together with the acoustic pressure intensity was above the input vibration detection signal.
[0034]
　The vibration sensor 43, the acceleration sensor, and MEMS acceleration sensor that applies MEMS (Micro Electro Mechanical System) technology, a piezoelectric type acceleration sensor, a sensor of various methods can be used.
[0035]
　Detection device 33 may be evaluated based on the intensity of the detected vibration, the input vibration detection signal and frequency analysis may be evaluated based on the spectral intensity of a specific frequency band. By using the spectral intensity, the noise component is high precision becomes possible rating to reduce. Further, by the synergistic effect with the evaluation based on the acoustic pressure intensity, it allows more reliable evaluation.
[0036]

　Next, a configuration for detecting the steering system single allophone.
　6 is an explanatory view showing an embodiment of detecting the steering system single allophone. In the illustrated example, it performs the abnormal sound detection while mounted alone the steering system 11 to the frame 51.
[0037]
　Pedestal 51 is provided with a rectangular bottom plate portion 53, a pillar portion 55 erected at each corner of the bottom plate portion 53 and a frame member 57 fixed to the upper end of the pillar portion 55, the steering system 11 the support in the same way as in-vehicle at the time.
[0038]
　The frame 51, vibrator 61 is provided. Vibrator 61 may optionally applying vibration to the steering system 11 supported by the frame 51. For example, by giving the same oscillation pattern and the vibration generated when the vehicle V is traveling in the steering system 11, steering system 11, the vibration is imparted applied during actual running while being supported by the frame 51. Although not shown, a portion imparting vibration may be a steering shaft 29 is a tie rod, vibration direction is not only the axial direction of the steering shaft 29 may be a vertical direction. It is also possible to vibrate the steering gear unit 25 in the vertical direction. Furthermore, may be vibrated individually above units, it may be simultaneously vibrated. This allows reproducible pseudo-running state to the steering system 11.
[0039]
　Also in this configuration, using a configuration similar to the microphone 31 and the detector (evaluation apparatus) 33 shown in FIG. 2, by measuring the sound generated from the steering system 11, steering system 11 along the human perception perform evaluation of. Further, using a microphone 31 and a vibration sensor 43 may be simultaneously evaluated for the steering system 11. In that case, it is possible to further improve the reliability of the evaluation results.
[0040]
　Thus, according to this method, without mounting a steering system 11 on the vehicle V, in a situation close to the time of travel of the vehicle V, and abnormal noise resulting from the steering system 11 accurately, it and reliably detected.
[0041]
　According to the different sound detection method described above, by arranging the microphone 31 to the position facing the end portion 45 of the column shaft 15, it can be reliably detected abnormal noise such as the rattling sound emitted from the steering system 11. Further, the rattling sound detection is difficult in a microphone placed in the ear position of the test driver, at an intensity in line with the human ear can be detected accurately. Also, even if there is no space for installing the microphone 31 in the lower part of the steering system 11, conveniently be attachable to the column shaft 15 can be improved freedom of abnormal noise inspection.
[0042]
　As described above, the present invention is not limited to the above embodiments, it or combining the components of the embodiments with each other, the description, and based on the well-known techniques, changes the person skilled in the art it is also the place where schedule of the present invention to apply, are included in the scope for which protection is sought.
Example
[0043]
　Here, describing the results of the vehicle V, and detects abnormal noise of the steering system 11 when caused to travel irregularities road, for example vehicle speed 15km / h.
[0044]
　As Example 1, using the microphone 31 disposed in a position facing the end portion 45 of the column shaft 15 to detect the sound emitted from the column shaft 15. The distance L between the column shaft 15 and a microphone 31 was set to 15mm. In Comparative Example 1, it was detected sound by a microphone placed in the ear position of the test driver.
[0045]
(Evaluation Results)
　FIG. 7 is a spectrogram of the detected sound signal in the first embodiment, FIG. 8 is a spectrogram of the detected speech signals in Comparative Example 1. As shown in FIG. 7, in Example 1, intermittent peaks are rattling noise component 500 Hz ~ 2000 Hz was detected. In Comparative Example 1 On the other hand, as shown in FIG. 8, intermittent peaks are rattling noise component is not clearly detected.
[0046]
　Figure 9 is a graph showing the average spectrum of Example 1 and Comparative Example 1. Comparing the average spectrum of Example 1 and Comparative Example 1 From the figure, in the first embodiment, a high dominant peak level in the 500 Hz ~ 2000 Hz.
[0047]
　Figure 10 is a frequency spectrum of the sound pressure of the first embodiment shown in FIG. 9 is a graph showing a spectrum when subjected to mask processing by the band-pass filter. As shown in the figure, when a mask processing performed by the band-pass filter 300 Hz ~ 5000 Hz, can selectively extract spectrum intensity of rattling noise component. As a result, it is possible to diagnosis and evaluation of the rattling noise in line with the hearing of the people.
[0048]
　As described above, the present specification discloses the following matters.
(1) having a column shaft for rotatably supporting the steering wheel, a abnormal sound detection method of the steering system for detecting abnormal noise from the steering system that steers the wheels in response to rotation of the column shaft,
　using a microphone which is arranged to face the column shaft end of the steering wheel side of the column shaft, the sound from the column shaft end measures,
　the steering system from the sound signal output from the microphone generating abnormal noise detection signal due to
abnormal sound detection method of the steering system.
　According to abnormal sound detection method of the steering system, the microphone facing the column shaft end, by measuring the sound from the column shaft end, it is amplified abnormal noise from the steering system, S / N ratio There can be detected with improved condition. Further, the sound signal of the measured sound, since the S / N ratio is large, can be easily detected abnormal sound caused by the steering system.
[0049]
(2) the abnormal sound detection method of the steering system according to the steering wheel is carried out in a state mounted on said column shaft (1).
　According to abnormal sound detection method of the steering system, can abnormal noise detected substantially in the same state as during actual traveling, the detection accuracy can be improved.
[0050]
(3) abnormal sound detection method of the steering system according the distance between said column shaft end microphone to 50mm or less (1).
　According to abnormal sound detection method of the steering system, by approximating the distance between the column shaft end and the microphone can measure the sound from the column shaft end with a larger sound pressure.
(4) between said column shaft end microphone is a space of only the air layer (1) to abnormal sound detection method of the steering system according to any one of (3).
　According to abnormal sound detection method of the steering system, without being shielded sound from the column shaft end, it can be directly measured.
[0051]
(5) determine the frequency spectrum of the measured sound by the microphone,
　the extracted signal spectral intensity of the frequency band of 300 Hz - 8 kHz of the frequency spectrum obtained and the abnormal sound detection signal (1) to (4) abnormal sound detection method of the steering system according to any one of.
　According to abnormal sound detection method of the steering system, since the rattle noise component can be selectively extracted from the sound signal of the measured sound may evaluate abnormal noise of the steering system more accurately.
[0052]
(6) the abnormal sound detection method of the steering system according to any one of to run a vehicle equipped with a steering system to detect the sound by the microphone (1) to (5).
　According to abnormal sound detection method of the steering system, can abnormal noise detection in a vehicle mounted state of the steering system, enabling more accurate evaluation.
[0053]
(7) the steering system mounted to the frame with a vibrator, said vibrator by performing detection of the sound by the microphone while applying vibration to the frame (1) to any one of (5) abnormal sound detection method of the steering system according to One.
　According to abnormal sound detection method of the steering system, pseudo able to detect abnormal noise during running of the steering system, easily perform the evaluation of noise generated.
[0054]
(8) has a column shaft for rotatably supporting the steering wheel, an evaluation device of the steering system for detecting abnormal noise from the steering system that steers the wheels in response to rotation of the column shaft,
　the column a microphone is placed against the column shaft end of the steering wheel side of the shaft,
　and supporting the steering system, the gantry comprising a vibrator for applying vibration,
　the vibration in the frame by the vibrator while applying, using the microphone, the sound from the column shaft end measures, a detection device for generating an abnormal sound detection signal caused from a sound signal to be output to the steering system from the microphone
comprises evaluation device of the steering system.
　According to the evaluation device of the steering system, pseudo able to detect abnormal noise during running of the steering system, easily perform the evaluation of noise generated.
[0055]
　This application is based on Japanese Patent Application filed April 21, 2016 (Japanese Patent Application No. 2016-85437), the contents of which are incorporated herein by reference.
DESCRIPTION OF SYMBOLS
[0056]
　11 Steering system
　13 steering wheel
　15 column shaft
　29 steering shaft
　31 microphone
　33 detector (evaluation
　device) 45 end (the column shaft
　end) 51 gantry
　61 vibrator
　S space
　V vehicle

The scope of the claims
[Requested item 1]
　Has a column shaft for rotatably supporting the steering wheel, a abnormal sound detection method of the steering system for detecting abnormal noise from the steering system that steers the wheels in response to rotation of the column shaft,
　the column shaft of using said microphone is placed against the column shaft end of the steering wheel side, the sound from the column shaft end measures,
　different due to the steering system from the sound signal output from the microphone generating a sound detection signal
abnormal sound detection method of the steering system.
[Requested item 2]
　Abnormal sound detection method of the steering system of claim 1 carried out in a state where the steering wheel is attached to the column shaft.
[Requested item 3]
　Abnormal sound detection method of the steering system according to claim 1 or claim 2 wherein the by traveling vehicle equipped with a steering system to detect the sound by the microphone.
[Requested item 4]
　Said steering system mounted to the frame with a vibrator, said vibrator by performing detection of the sound by the microphone while applying vibration to the cradle
different steering system according to claim 1 or claim 2 sound detection method.
[Requested item 5]
　It has a column shaft for rotatably supporting the steering wheel, an evaluation device of the steering system for detecting abnormal noise from the steering system that steers the wheels in response to rotation of the column shaft,
　the said column shaft a microphone is placed against the column shaft end of the steering wheel side,
　the steering system supported, the pedestal comprising a vibrator for applying vibration,
　while applying vibration to the cradle by the vibrator , using the microphone, the sound from the column shaft end measures, a detection device for generating an abnormal sound detection signal caused from a sound signal to be output to the steering system from the microphone
of the steering system comprising evaluation device.