JP5623774B2 - Tire noise measuring device - Google Patents

Description

  The present invention relates to a tire noise measuring device.

  Conventionally, by providing a pseudo road surface in which the aggregate used on the ISO road surface is hardened with a binder of epoxy resin on the outer peripheral surface of the drum body, tire noise having a high correlation with the tire noise test result on the ISO road surface by an actual vehicle 2. Description of the Related Art A tire test drum used in a tire noise test apparatus for which a test result is to be obtained is known (see, for example, Patent Document 1).

  Further, a bench test method having a high correlation with an actual vehicle is known (for example, see Patent Document 2).

JP 11-218470 A Japanese Unexamined Patent Publication No. 7-55649

  However, in the tire noise test apparatus of the above example, sound is reflected by the floor surface. Therefore, the sound reflected by the floor is included in the sound measured by the microphone as the sound measuring means of the tire noise test apparatus. The tire noise test result obtained in such a case has a low correlation with the tire noise test result on a predetermined road surface by an actual vehicle, and a tire noise test that can obtain a more accurate test result is desired. Yes.

  The reflection of sound from the floor can be improved by increasing the distance between the drum tester and the noise measurement microphone. In this case, however, the size of the tire noise test device is large. It becomes inconvenient. Furthermore, it is conceivable to change the floor surface itself to a member having a sound absorbing function. However, in this case, the place for the tire noise test is limited, and the cost is very high.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tire noise measuring device capable of obtaining a more accurate tire noise test result.

In order to achieve the above object, the tire noise measuring device according to the first aspect of the present invention has a drum provided on the floor and rotating the tire in contact with the outer peripheral surface, and a sound absorbing effect on the road surface of the actual vehicle. As reproduced, on the floor surface within a predetermined range from the drum side end of the floor surface between the drum and a measurement position for measuring the sound generated from the tire rotated by the drum . A sound-absorbing member that absorbs sound, disposed at least in part, and a sound-measuring means that measures sound generated from the rotated tire and partially absorbed by the sound-absorbing member, disposed at the measurement position And.

According to the tire noise measurement apparatus of the present invention, it is absorbed sound generated from the tire by the sound absorbing member, because the absorbing effect of the sound in the traveling road surface of the vehicle is reproduced, according to the floor surface by the sound absorbing member is disposed Compared to the case where the sound reflection is suppressed and no sound absorbing member is arranged, the ratio of the sound reflected from the floor surface included in the sound measured by the sound measuring means is reduced, and a more accurate tire noise test result is obtained. Can be obtained.

Further, the tire noise measuring device according to the second aspect of the invention is configured such that when the sound is measured at each of the plurality of measurement positions along a direction along the floor surface and intersecting with the rotation axis of the tire, the sound absorbing member is provided. but Ru disposed on at least a portion on the floor surface in the periphery a and the predetermined range of the drum.

As described above, according to the tire noise measurement apparatus of the present invention, it is possible to obtain a more accurate tire noise test results, which have the effect that.

It is a schematic block diagram which shows an example of the tire noise test apparatus of this Embodiment. It is a top view which shows an example of the tire noise test apparatus of this Embodiment. Relationship graph between tire noise test results measured by the tire noise test apparatus according to the present embodiment, tire noise test results measured by a conventional method in which no sound absorbing member is disposed on the floor surface F, and actual vehicle test results ( It is a figure which shows the correlation graph in OA value.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1A, FIG. 1B, and FIG. 2 show a state where the tire 3 to be tested is mounted on the tire noise test apparatus 10 according to the present embodiment. FIG. 2 is a plan view of the tire noise test apparatus 10.

  A tire noise test apparatus 10 according to the present embodiment is provided on a floor surface F, and rotates a drum 4 that is brought into contact with the outer peripheral surface, and a sound generated from the rotated tire 3. A microphone 2 and a sound absorbing member 11 that is disposed on at least a portion of the floor surface F within a predetermined range (for example, within a radius of 0.4 m) from the position F_3 of the floor surface F on which the drum 4 is provided and that absorbs sound. It has. The drum 4 is an example of a rotating device, and the microphone 2 is an example of sound measurement means.

  Here, in the present embodiment, a part of the sound absorbing member 11 is a floor between the drum 4 (position F_3 on the floor surface F where the drum 4 is provided) and the position F_2 where the microphone 2 is projected onto the floor surface F. Arranged on the surface F.

  The distance parallel to the rotation axis 6 from the equator plane 7 of the tire 3 to the microphone 2 is 1 m, and the height of the microphone 2 from the drum surface 5 is 0.25 m. In addition, the value of this distance and height is an example, and is not limited to the value demonstrated above.

In the tire noise test by the tire noise test apparatus 10, the microphone 2 is moved at a plurality of K positions in a section of the tire 3 in the front-rear direction 2m (for example, the microphone 2 is moved in 4 cm increments by a moving mechanism not shown) The sound pressure level is measured (at 51 locations in this case). Similar to the technique described in Japanese Patent Laid-Open No. 7-55649, the following equation (1) is shown based on the _K measured sound pressure levels P _{1 to} P _K dB (A). Thus, the average value is calculated, and the calculated average value is used as the evaluation value.

図３に、本実施の形態のタイヤ騒音試験装置１０によって測定されたタイヤ騒音試験結果、及び吸音部材１１を床面Ｆに配置しない従来技術の方法によって測定されたタイヤ騒音試験結果と、実車試験結果との関係グラフ（ＯＡ値での相関関係グラフ）を示す。

FIG. 3 shows a tire noise test result measured by the tire noise test apparatus 10 of the present embodiment, a tire noise test result measured by a conventional method in which the sound absorbing member 11 is not disposed on the floor surface F, and an actual vehicle test. The relationship graph (correlation graph by OA value) with a result is shown.

  According to this relationship graph, the tire noise test result measured by the tire noise test apparatus 10 of the present embodiment is closer in tendency to the actual vehicle test result than the tire noise test result measured by the conventional method. It can be seen that the degree of correlation is good.

  In this relational graph, for example, the standard error of 0.76 dB (A) in the conventional technique is 0.69 dB (A) in the tire noise test apparatus 10 of the present embodiment, and the sound absorption is performed. It can be seen that the tire noise test result measured by the tire noise test apparatus 10 of the present embodiment is more accurate than the prior art in which the member 11 is not disposed.

  As described above, according to the tire noise test apparatus 10 of the present embodiment, the sound generated from the tire 3 is absorbed by the sound absorbing member 11, and the sound is not reflected by the floor surface F of the portion where the sound absorbing member 11 is disposed. Therefore, compared with the case where the sound absorbing member 11 is not disposed, the ratio of the sound reflected from the floor surface F included in the sound measured by the microphone 2 is reduced, and a more accurate tire noise test result can be obtained. .

  In addition, in order to reproduce the sound absorption effect on the road surface of the actual vehicle by arranging the sound absorbing member 11, use a replaceable material for the indoor test road surface as long as the road surface material is close to the actual vehicle road surface. Therefore, it can be replaced when the evaluation road surface is worn, and it has excellent maintainability.

  The tire noise test apparatus 10 according to the present embodiment has been described above. In the above, a part of the sound absorbing member 11 is on the floor surface F between the drum 4 (position F_3 on the floor surface F where the drum 4 is provided) and the position F_2 where the microphone 2 is projected onto the floor surface F. Although the example in which the sound absorbing member 11 is arranged has been described, the entire sound absorbing member 11 is located on the floor surface between the drum 4 (position F_3 on the floor surface F where the drum 4 is provided) and the position F_2 where the microphone 2 is projected onto the floor surface F. It may be arranged on F.

  Further, the position where the sound absorbing member 11 is disposed is reflected from the floor surface F included in the sound measured by the microphone 2 when the sound absorbing member 11 is disposed, as compared with the case where the sound absorbing member 11 is not disposed. Any position may be used as long as the sound ratio is small.

2 Microphone 3 Tire 4 Drum 5 Drum surface 6 Rotating shaft 7 Equatorial surface 10 Tire noise device 11 Sound absorbing member F Floor surface

Claims (2)

A drum provided on the floor and rotating the tire in contact with the outer peripheral surface;
Predetermined from the drum-side end of the floor surface between the drum and a measurement position for measuring the sound generated from the tire rotated by the drum so that the sound absorption effect on the road surface of the actual vehicle is reproduced. A sound absorbing member that absorbs sound, disposed on at least a portion of the floor within a range ;
Sound measuring means that is arranged at the measurement position and that measures the sound generated from the rotated tire and partly absorbed by the sound absorbing member;
Tire noise measuring device equipped with. When measuring sound at each of the plurality of measurement positions along a direction along the floor surface and intersecting the rotation axis of the tire,
It said sound absorbing member is surrounding at and least tire noise measuring apparatus of a portion to placed according to claim 1, wherein on the floor within the predetermined range of the drum.

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