JPS6111656A - Measuring device for logarithmic attenuation factor - Google Patents
Measuring device for logarithmic attenuation factorInfo
- Publication number
- JPS6111656A JPS6111656A JP59131981A JP13198184A JPS6111656A JP S6111656 A JPS6111656 A JP S6111656A JP 59131981 A JP59131981 A JP 59131981A JP 13198184 A JP13198184 A JP 13198184A JP S6111656 A JPS6111656 A JP S6111656A
- Authority
- JP
- Japan
- Prior art keywords
- cover
- test piece
- piece
- test
- geophone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H1/00—Measuring characteristics of vibrations in solids by using direct conduction to the detector
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/11—Analysing solids by measuring attenuation of acoustic waves
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
Description
【発明の詳細な説明】
イ 発明の目的
（産業上の利用分野）
この発明は、ブレーキ用摩擦材のような材料の対数減衰
率を各種温度状態において測定できる対数減衰率測定装
置に関する。DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (Field of Industrial Application) This invention relates to a logarithmic attenuation rate measuring device that can measure the logarithmic attenuation rate of a material such as a brake friction material under various temperature conditions.
（従来の技術）
例えば、自動車のブレーキ用摩擦材において、その対数
減衰率は、制動時の騒音発生に大きな関連性を持ってい
る。従って摩擦材の対数減衰率を知ることは、騒音のな
いブレーキ装置を造る上に必要である。(Prior Art) For example, in friction materials for automobile brakes, the logarithmic damping rate has a great relationship with noise generation during braking. Therefore, it is necessary to know the logarithmic damping rate of the friction material in order to create a noise-free brake system.
ブレーキ用摩擦材の温度は制動時の発熱のため変化する
。即ちブレーキ使用頻度、自動車あ速度等に影響されて
変化する。また寒冷地で使用するときは低温で使用され
るから、各種温度における対数減衰率を知ることも重要
である。The temperature of brake friction materials changes due to heat generation during braking. That is, it changes depending on the frequency of brake use, vehicle speed, etc. Furthermore, when used in cold regions, it is used at low temperatures, so it is important to know the logarithmic decay rate at various temperatures.
従来、摩擦材の対数減衰率測定は第４〜５図のようにし
て行なわれていた。Conventionally, the logarithmic damping rate of friction materials has been measured as shown in FIGS. 4 and 5.
第４図に示した方法は、２本吊りと呼ばれる方法で、短
冊形に形成した摩擦材の試験片１を、振動エネルギの損
失を避けるため振動の節となる位置において２本の吊糸
２．２で吊下げ、試験片ｌの一端に加振器３で振動を加
え、試験片の他端に受振器４を接近させて試験片の振動
状態を測定するものである。加振器３、受振器４には、
必要な発振器、周波数カウンタ０、増幅器、オッシログ
ラフ等が付設される。The method shown in Fig. 4 is a method called two-string hanging, in which a friction material test piece 1 formed into a rectangular shape is placed between two hanging strings 2 at vibration node positions to avoid loss of vibration energy. .2, vibration is applied to one end of the test piece l using a vibrator 3, and a vibration receiver 4 is brought close to the other end of the test piece to measure the vibration state of the test piece. The exciter 3 and geophone 4 include
Necessary oscillators, frequency counters, amplifiers, oscilloscopes, etc. are attached.
第５図に示した方法は、」−記の吊糸２．２の代りに、
支持台５の上面に設けたナイフェツジ６．６により短冊
状試験片ｌの振動の節となる位置を支持し、加振器３、
受振器４により試験片１の振動状態を測定するものであ
る。The method shown in FIG.
A knife 6.6 provided on the upper surface of the support stand 5 supports the vibration node position of the strip-shaped test piece l, and the vibration exciter 3,
The vibration state of the test piece 1 is measured using a geophone 4.
（発明が解決しようとする問題点）
第４図の２本吊り法は、試験片を柔軟な糸で吊るという
簡単な支持法であり、且つ試験片の振動が支持部の剛性
の影響を受けないので、測定誤差が少ないという利点が
あるけれども、高温時の振動減衰率測定のため吊下げた
試験片を熱風により加熱すると、吊糸が揺れて、振動の
節となる位置での支持からずれたり、試験片が揺れ動く
ので加振、受振を正確に行ない難くなる。(Problem to be solved by the invention) The two-hanging method shown in Fig. 4 is a simple supporting method in which the test specimen is suspended by a flexible thread, and the vibration of the test specimen is not affected by the rigidity of the support. However, when a suspended test piece is heated with hot air to measure the vibration damping rate at high temperatures, the hanging string sways and deviates from its support at vibration nodes. In addition, the test piece may sway, making it difficult to excite and receive vibrations accurately.
また、通常の糸を使用しているので、高温時に切、断す
ることが多い。さらに、加振器、受振器共に熱風に曝さ
れるが、これらの装置は高温雰囲気（約１５０℃以上）
中で長時間使用できない。Also, since it uses regular thread, it often breaks or breaks at high temperatures. Furthermore, both the exciter and the geophone are exposed to hot air, but these devices operate in a high-temperature atmosphere (approximately 150°C or higher).
It cannot be used inside for a long time.
第５図のようにナイフェツジ６で試験片１を支えると、
熱風のため試験片が揺れ動くことは避けられ、吊糸切断
の心配も無いが、熱のため試験片が変形すると、振動の
節の位置での支持ができなくなり正確な測定が困難にな
る。When the specimen 1 is supported by the knife 6 as shown in Fig. 5,
Although the hot air prevents the test piece from shaking and there is no need to worry about the suspension string breaking, if the test piece deforms due to the heat, it will no longer be able to support the test piece at the vibration nodes, making accurate measurements difficult.
口 発明の構成
この発明の装置は、支持台の上に横に掛渡した撓みの少
ない２本の耐熱性繊維の糸に振動の節を合致させて短冊
状の試験片を載せ、試験片の両端部分ヲ除いてカバーで
覆い、カバーから出た試験片端部にカバーの外に置いた
加振器、受振器を対向させ、カバー内に熱気または冷気
を流入させて試験片を加熱または冷却して、この状態で
対数減衰率を測定するように構成したものである。Structure of the Invention The apparatus of the present invention places a strip-shaped test piece on two low-deflection heat-resistant fiber threads that are stretched horizontally on a support stand, with vibration nodes aligned with each other. Cover the test piece with a cover except for both ends, place a vibrator and a geophone placed outside the cover to face the end of the test piece protruding from the cover, and heat or cool the test piece by flowing hot or cold air into the cover. The structure is such that the logarithmic attenuation rate is measured in this state.
（作 用）
、 カバー外に突出した短冊形試験片の一端に加振器
により振動を与え、試験片の他端の振動を受振、器で測
定することにより、材料の対数減衰率を測定することが
できる。(Function) The logarithmic damping rate of the material is measured by applying vibration to one end of the rectangular test piece protruding outside the cover using a vibrator, receiving the vibration at the other end of the test piece, and measuring it with a device. be able to.
常温における材料の対数減衰率は、上記の通りにして測
定できるが、高温または低温における対数減衰率測定は
、ケース内に高温または低温空気を送って試験片の温度
を高くまたは低くして行なう。カバー内に吹込んだ熱風
または冷風は、試験片がカバーから突出する部分のカバ
ーとの間隙からカバー外に出るようにされて、試験片の
表面に沿って流れるから、試験片を均一に加熱または冷
却する。試験片を支える糸は、ケブラー、コーネックス
（商品名）等の耐熱繊維糸を使用するから、高温での測
定も良好に行なえる。カバーの材質は、断熱性のもので
あることが望ましい。The logarithmic decay rate of a material at room temperature can be measured as described above, but the logarithmic decay rate measurement at high or low temperatures is performed by sending hot or cold air into the case to raise or lower the temperature of the test piece. The hot or cold air blown into the cover is forced to exit the cover through the gap between the cover and the part where the test piece protrudes from the cover, and flows along the surface of the test piece, heating the test piece evenly. Or cool. Since the thread supporting the test piece is a heat-resistant fiber thread such as Kevlar or Conex (trade name), measurements at high temperatures can be performed well. It is desirable that the material of the cover is heat insulating.
（実 施 例）
第１〜３図は本発明の実施例を示し、第１図はケースを
縦断した正面図、第２図は第１図のＡ−Ａ線による支持
台部の断面図、第３図はケースを除いた要部の斜視図で
ある。(Example) Figures 1 to 3 show examples of the present invention, where Figure 1 is a front view taken longitudinally of the case, Figure 2 is a sectional view of the support part taken along line A-A in Figure 1, FIG. 3 is a perspective view of the main parts excluding the case.
支持台５の四隅には突片７．７が形成されており、前後
の突片７．７の間に撓みを少なくして、ケブラー、コー
ネックス等の耐熱性繊維による支持糸８が掛渡されてい
る。第２図に見るように支持糸８の撓みａの大きさは、
これが掛渡された突片７．７の内側寸法文に対してａ＝
０．０３１〜０．０５ｆ！、の範囲にされる。Projections 7.7 are formed at the four corners of the support base 5, and support threads 8 made of heat-resistant fibers such as Kevlar and Conex are strung between the front and rear projections 7.7 to reduce deflection. has been done. As shown in Fig. 2, the magnitude of the deflection a of the support thread 8 is:
This is a=
0.031~0.05f! , within the range of .
支持台５には、これを覆うカバー９をかぶせる。カバー
９には、上部に空気人口１０を形成し、支持糸８に載せ
、た試験片１の両端部を突出させる通孔１１．１１を開
口させる。加振器３、受振器４は、カバー９の外にあっ
て、試験片１の両端部下面に対向させる。The support stand 5 is covered with a cover 9. The cover 9 is provided with through holes 11, 11 in the upper part of which are formed air holes 10 and through which both ends of the test piece 1 placed on the support thread 8 protrude. The vibration exciter 3 and the vibration receiver 4 are located outside the cover 9 and are opposed to the lower surface of both ends of the test piece 1 .
このように構成するから、支持糸８．８に振動の節を合
致させて試験片ｌを載せ、空気入口１０から熱風をカバ
ー９内に吹込むと、熱風はカバー内および試験片１を昇
温させ、通孔１１からカバー外に排出される。この際、
熱風はカバー内から両側の通孔１１に向けて試験片１の
表面に沿って流れ、通孔１１を出てからちケース外にあ
る試験片端部を覆って流れるので試験片各部を均一に昇
温させる。With this structure, when the test piece 1 is placed on the supporting thread 8.8 with the nodes of vibration aligned and hot air is blown into the cover 9 from the air inlet 10, the hot air rises inside the cover and up the test piece 1. It is heated and discharged from the through hole 11 to the outside of the cover. On this occasion,
The hot air flows from inside the cover toward the through holes 11 on both sides along the surface of the test piece 1, and after leaving the through hole 11, it flows over the ends of the test piece outside the case, so that each part of the test piece is evenly raised. Warm up.
この状態で試験片ｌを加熱し、所定温度になったならば
加振器３で試験片ｌを振動させ、これの減衰状態を受振
器４で測定して材料の対数減衰率を知ることができる。In this state, the test piece l is heated, and when it reaches a predetermined temperature, the test piece l is vibrated with the vibrator 3, and the damping state of this is measured with the geophone 4, to find out the logarithmic damping rate of the material. can.
空気入口１０から、冷風を吹込んで試験片ｌを冷却すれ
ば、材料の低温時の対数減衰率を測定することができる
。By blowing cold air through the air inlet 10 to cool the test piece I, the logarithmic decay rate of the material at low temperature can be measured.
支持糸８は、撓みが少ないので殆ど揺れ動くことが少な
く、試験片の振動の節から外れることがない。また加振
器３、受振器４はケース外にあるので熱風の悪影響を受
けることがなく、測定誤差を生じない。Since the support thread 8 has little flex, it hardly swings and does not come off the vibration nodes of the test piece. Furthermore, since the vibrator 3 and the geophone 4 are located outside the case, they are not adversely affected by hot air, and measurement errors do not occur.
ハ 発明の効果
（＋）支持台および試験片の大部分をカバーで覆うので
、試験片の加熱、冷却を良好に行なえる。C. Effects of the invention (+) Since most of the support stand and the test piece are covered with a cover, the test piece can be heated and cooled well.
（２）加振器、受振器は、冷熱の影響を受けないので良
好な測定ができる。(2) Since the vibrator and geophone are not affected by cold or heat, good measurements can be made.
（３）支持糸は撓みが少ないのでカバー内の気流のため
殆ど揺れず、振動の節位置から移動することがなく、良
好な測定ができ・る。(3) Since the support thread has little deflection, it hardly sways due to the airflow inside the cover, and does not move from the vibration node position, allowing for good measurements.
（４）支持糸として耐、熱性のある繊維の糸を使用する
ので、高温での測定ができる。(4) Since a fiber thread having heat resistance and heat resistance is used as the support thread, measurements can be performed at high temperatures.
第１図は本発明の対数減衰率測定装置を示すカバーを縦
断した正面図、第２図は第１図のＡ−Ａ線による支持台
部の断面図、第３図はカバーを除いた要部の斜視図、第
４〜５図は従来の測定法を示し、第４図は２本吊り法を
示す略正面図、第５図はナイフェツジ支持法の要点を示
す略正面図である。
１：試験片、２：吊糸、３：加振器、４：受振器、５：
支持台、６：ナイフェツジ、７：突片、８：支持糸、９
：カバー、１０：空気入口、１１：通孔。Fig. 1 is a front view taken longitudinally through the cover showing the logarithmic attenuation rate measuring device of the present invention, Fig. 2 is a cross-sectional view of the support section taken along line A-A in Fig. 1, and Fig. 3 is the main part excluding the cover. FIG. 4 is a schematic front view showing the two-piece suspension method, and FIG. 5 is a schematic front view showing the main points of the knife support method. 1: Test piece, 2: Hanging string, 3: Vibrator, 4: Geophone, 5:
Support stand, 6: knife, 7: protrusion, 8: support thread, 9
: Cover, 10: Air inlet, 11: Through hole.
Claims (1)
の節に合致させて支持する耐熱性繊維の２本の支持糸（
８）（８）を撓みを少なくして横に掛渡し、空気入口（
１０）および試験片（１）の両端を突出させる通孔（１
１）（１１）を設けたカバー（９）で着脱自在に支持台
（５）を覆い、カバー（９）の外において、試験片（１
）の両端部に対応する位置に加振器（３）、受振器（４
）を設けた対数減衰率測定装置。On the support stand (5), two supporting threads (
8) Hang (8) horizontally with less bending, and connect the air inlet (
10) and a through hole (1) through which both ends of the test piece (1) protrude.
1) Cover the support stand (5) removably with the cover (9) provided with (11), and place the test piece (1) outside the cover (9).
) and a vibration exciter (3) and a geophone (4) at positions corresponding to both ends of the
) logarithmic attenuation rate measuring device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59131981A JPS6111656A (en) | 1984-06-28 | 1984-06-28 | Measuring device for logarithmic attenuation factor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59131981A JPS6111656A (en) | 1984-06-28 | 1984-06-28 | Measuring device for logarithmic attenuation factor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6111656A true JPS6111656A (en) | 1986-01-20 |
| JPH047830B2 JPH047830B2 (en) | 1992-02-13 |
Family
ID=15070754
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59131981A Granted JPS6111656A (en) | 1984-06-28 | 1984-06-28 | Measuring device for logarithmic attenuation factor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6111656A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2757361A1 (en) * | 2013-01-21 | 2014-07-23 | Rolls-Royce plc | A Test Apparatus and a Method of Testing |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3435044A1 (en) * | 2017-07-27 | 2019-01-30 | Aif Management Bvba | Apparatus and method for performing an impact excitation technique |
-
1984
- 1984-06-28 JP JP59131981A patent/JPS6111656A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2757361A1 (en) * | 2013-01-21 | 2014-07-23 | Rolls-Royce plc | A Test Apparatus and a Method of Testing |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH047830B2 (en) | 1992-02-13 |
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