WO1989001138A1 - Method of measuring contact stress with ultrasonic wave - Google Patents
Method of measuring contact stress with ultrasonic wave Download PDFInfo
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- WO1989001138A1 WO1989001138A1 PCT/JP1987/000564 JP8700564W WO8901138A1 WO 1989001138 A1 WO1989001138 A1 WO 1989001138A1 JP 8700564 W JP8700564 W JP 8700564W WO 8901138 A1 WO8901138 A1 WO 8901138A1
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- WIPO (PCT)
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- wave
- contact
- contact surface
- probe
- thin plate
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/25—Measuring force or stress, in general using wave or particle radiation, e.g. X-rays, microwaves, neutrons
- G01L1/255—Measuring force or stress, in general using wave or particle radiation, e.g. X-rays, microwaves, neutrons using acoustic waves, or acoustic emission
Definitions
- the present invention relates to a method for measuring a contact stress at a contact surface between a thin plate in contact with another object using an ultrasonic wave.
- thin plate refers to a thin member whose thickness (mainly 2 to 3 mm or less and up to about lonra) through which a plate wave can propagate, and whose shape is a band shape, plate shape, or other planar shape. Needless to say, it also includes a cylindrical shape such as a tube material and a curved shape of a member having a curved surface portion.
- the thin plates and other solids in contact are metals and non-metals (glass, ceramics, synthetic resin, etc.) through which ultrasonic waves can propagate, and the contact state is, for example, a band.
- FIG. 9 and FIG. 10 are explanatory views of a typical embodiment of the measuring method described in PCTZJP 82 Z 00087.
- FIG. 9 is a diagram showing a method of using a metal (for example, a boss made of carbon steel for a mechanical structure). This is an example of measuring the contact stress on the mating surface (contact surface) when press-fitting (for example, a carbon steel pipe for machine structure).
- 1 is a pulse reflection type ultrasonic flaw detector
- 2 is a probe (in this case, a vertical probe).
- the incident ultrasonic wave 3 is reflected by the contact surface 4.
- the reflected wave on the bottom surface of the metal ⁇ does not transmit through the contact surface 4 but is reflected by the contact surface 4 and the metal! [It is divided into those that repeat reflection within.
- the first reflected wave S received by the probe 2 has the following thickness on the CRT of the ultrasonic flaw detector 1 at the position of the transmission pulse 5 as shown in Fig. 10 tt to appear as a echo corresponds to the time T t has elapsed echo height h B l to the position after the second reflected wave 7, the position of the same Ku transmission pulse 5 Appearing as a ⁇ echo echo height h Pl to position after the time T 2 has elapsed, corresponding to the thickness t 2 of the Li metal [pi.
- the comparison value between the height h Bl of the appearing Bi echo and the length h Pl of the Pi echo is
- ⁇ h (dB) can be obtained depending on the difference between the echo height and the Pi echo height.
- the comparative value A h obtained is put into an empirical formula that shows a linear correlation with the logarithm of the difference A h between the contact stress and the echo height, which is confirmed in advance by experiments; Or from a graph created by calculating empirical formulas.
- PCT / JP 82 00087 shows a specific method for comparing the sound level of the reflected wave reflected from the contact surface 4 with the sound pressure of the transmitted wave transmitted through the contact surface 4 as shown in FIG. 9 above.
- a vertical probe for transmission abuts on the outer surface of Metal I, and a vertical probe for reception to receive transmitted waves is placed on the bottom of Metal ⁇ .
- Ultrasonic waves (in this case, jl waves) are input and emitted from the direction, and both the reflected waves from the contact surface 4 and the transmitted waves transmitted through the contact surface 4 receive the ultrasonic waves emitted at an oblique angle with the oblique probe.
- the method differs from the method in which the probe is in direct contact with the surface of metal I and ⁇ ⁇ , and the distance between the subject and the probe is different.
- the thickness dimension of the solid I and the solid ⁇ in contact is determined by the difference between the echo of the reflected wave from the contact surface 4 and the contact surface 4. It is necessary that the thickness be such that the transmitted transmitted echo and the transmitted wave can be clearly separated and measured.
- the contact surface 4 between a thin plate having a thickness of 2 to 3 brittle or less and another solid not only the rain echo of the reflected wave and the transmitted wave are not clearly separated, but also Since it is not possible to perform y measurement that overlaps with the transmitted wave, in such a case, use a liquid immersion method that has a short minimum flaw detection distance, is easy to use at high frequencies, and allows flaw detection of thin materials. become.
- the environmental conditions during use of the object to be measured directly affect the measurement object if the object cannot be immersed in the liquid tank.
- it is essential to prepare an immersible liquid tank in accordance with the dimensions, shape, material, etc. of the object to be measured. It is limited to the size of. Therefore the object of measurement is limited to relatively small components to scale, the measurement equipment in difficult working sites like the preparation of the liquid bath is restricted, such as practically impossible t
- it is necessary to maintain the distance between the probe and the flaw detection surface of the object to be measured at a constant level for scanning, which makes the structure and measurement of the device complicated, simple, and real-time.
- the direct contact method and the liquid immersion method are not used, and the bottom surface for reflecting the transmitted wave transmitted through the contact surface 4 on the object to be measured or the probe for receiving the transmitted wave is used.
- the bottom surface is required to be in contact with the contact surface 4 and the bottom surface is far away from the contact surface 4, or when the bottom surface is not obtained because it is integrated with other structures, etc. In some cases, reflected waves and transmitted waves required for measurement cannot be obtained and measurement may not be possible.
- the present invention solves the above-mentioned problems of the prior art, and enables a quantitative, short-time and real-time evaluation without changing the contact state and properties of the contact surface to be measured. It is a basic object of the present invention to provide a method for measuring the contact stress of a contact surface between a thin plate and another solid by ultrasonic waves.
- Another object of the present invention is to continuously measure the distribution of the contact stress on the contact surface to be measured and to monitor the dynamic contact stress on the contact surface to be measured in a sliding or rotating state.
- An object of the present invention is to provide a method for measuring contact stress of a contact surface between a thin plate and another solid by using ultrasonic waves.
- the present invention detects thin plates in contact with other thin plates
- the probe makes contact with the probe, ultrasonic waves are incident on the thin plate from the probe to generate a plate wave, and the generated plate wave propagates through the thin plate and passes through the contact surface. It is characterized by measuring the contact stress at the contact surface using the pressure as an evaluation index.
- a feature of the present invention is to utilize a property that has a certain correlation between contact stress at a contact surface between a thin plate and another solid and sound pressure of a plate wave received through the contact surface.
- a description will be given below with reference to FIGS. 1 and 2.
- 8 is a thin plate.
- a shear wave is applied to the thin plate 8 from the point of incidence 10 in the state where contact stress and stress are generated on the contact surface 4 of width B shown in the figure, under certain conditions, that is, the frequency of the incident transverse wave minus the thin plate 8
- a sheet wave of a mode determined by the relationship between the sheet thickness and the Poisson's ratio is generated in the thin plate 8.
- the generated plate wave 12 propagates through the thin plate 8, passes through the contact surface 4, and then emerges from the exit point 11, which is separated from the incident point 10 by an interval ⁇ , but the plate wave 12 at the exit point 11 is While passing through, the wave is constrained under the influence of the contact stress ⁇ , and at the same time, propagates through the contact surface 4 to other solids and is diffused and emitted as an attenuated plate wave 13.
- the attenuation of the plate wave 12 is also caused by the radiation of the microwave energy from the outer surface of the thin plate 8 at the distance ⁇ from the incident point 10 to the output point 11, that is, the propagation distance of the wave.
- an echo pattern as shown in FIG. 2 is obtained. That is, it appears as a P echo having an echo height h at a position after the elapse of the time t corresponding to the interval ⁇ from the position of the transmission pulse T at the origin.
- the height h of the P echo is such that the contact stress ⁇ is large.
- the wave constraint on the bow 4 increases, and the decay increases in proportion to the height of the constraint.
- the width B of the contact surface 4 increases, the width of the contact increases.
- ⁇ the height h of the echo is a function of the contact stress h, the width B of the contact surface 4 and the propagation distance of the plate wave ⁇ , and these relationships are expressed by the following relational expressions. h 0 ⁇ . B ⁇ . ⁇ ' ⁇ ⁇ ⁇ ' ⁇ (1)
- the above equation (1) shows that the height h of the received echo ( ⁇ echo) is inversely proportional to the product of the contact stress ⁇ , the width of the contact surface 4 ⁇ , and the propagation distance of the plate wave ⁇ .
- the width ⁇ of the contact surface 4 and the propagation distance ⁇ of the plate wave are constant once the DUT is specified, so the height h of the receiving echo is a function of only the contact stress ⁇ , and It becomes a simple engagement equation.
- the measuring method of the present invention utilizes the relationship of the above equation (2), that is, the relationship in which the length h of the reception echo is inversely proportional to the contact stress ⁇ .
- the relationship between the height h of the received echo and the contact stress ⁇ has been verified to have a logarithmic linear relationship in an experiment described later, and therefore, the state where the contact stress ⁇ is generated Suffered
- the contact stress ⁇ can be quantitatively evaluated simply by measuring the height h of the received echo of the DUT, and the sound pressure reflected from the contact surface and the contact surface
- the contact stress at the contact surface between the thin plate and the other solid is easier than using a liquid bath in which the object is immersed, as compared with the case of evaluating by comparing the sound pressure of the transmitted wave transmitted through the object.
- it has features that can be evaluated in real time.
- the contact stress ⁇ is generated over a wide width in a direction perpendicular to the width ⁇ of the contact surface 4 shown in FIG.
- the distribution state of the contact stress ⁇ can be continuously measured.
- a plurality of incident points 10 and outgoing points 11 may be juxtaposed in the right-angle direction, and measurement may be performed simultaneously or extremely.
- the measurement method of the present invention is based on the assumption that the thin plate 8 and the other solid 9 are in a sliding or sliding state, such as a thin-walled cylinder and a rotating body rotating around its outer periphery, and the contact stress ⁇ ?
- a sliding or sliding state such as a thin-walled cylinder and a rotating body rotating around its outer periphery
- a transmitting (or receiving) probe is placed on the thin plate on the side, and a receiving (or transmitting) probe is placed on the thin plate on the side opposite to the contact surface 4. is there.
- the arrangement of the probe is relatively different from that of the contact surface 4, the sound pressure of the plate wave obtained when the propagation distance ⁇ is the same is the same, and the contact Either method can be selected and used according to the situation around the touch surface 4.
- FIG. 1 is an explanatory view of the principle of the measuring method of the present invention
- FIG. 2 is an explanatory view of an echo pattern on a CRT of a received echo obtained by the method of FIG.
- FIG. 3 is a schematic explanatory diagram of an embodiment of the present invention
- FIG. 4 is a schematic explanatory diagram of an experiment conducted to verify the effect of the measurement method of the present invention
- FIG. 5 is a VV arrow of FIG. Fig. 6 is a graph showing the relationship between contact stress and echo height based on the results of the experiment shown in Fig. 4.
- FIG. 7 and 8 show another embodiment of the measuring method of the present invention, and are schematic explanatory diagrams similar to FIG.
- FIG. 9 is an example of a conventional method for measuring the contact stress of a solid contact surface using ultrasonic waves, and is an explanatory diagram described in PCT / JP 82 Z 00087.
- FIG. 4 is an explanatory diagram showing an echo pattern on a CRT obtained.
- reference numeral 8 denotes a thin plate (for example, a thin tube), and 9 denotes a solid having a width B in contact with the thin plate 8 at the contact surface 4 (for example, the tube is solidified).
- the contact surface 4 is pressed and a contact stress ⁇ is generated at ⁇ B.
- 14 is a transmitting probe for exciting a plate wave (in this case, a Lamb wave) 12 on the thin plate 8
- 15 is a pair of scissoring surfaces 4, and abutting the probe 14 against the thin plate 8 at an interval ⁇ . This is the receiving probe.
- a transverse wave is incident on the thin plate 8 from the incident point 10 through the wedge of the probe 14.
- a mode plate wave 12 is generated in the thin plate 8, which is determined by the relationship between the frequency of the incident transverse wave and the thickness of the thin plate 8 minus the Poisson's ratio of the thin plate 8.
- the generated wave 12 simulates the thin plate 8, passes through the contact surface 4 on the way, reaches the emission point 11 and is received by the probe 15, but the received plate wave 13 is affected by the contact surface 4.
- the frequency is selected according to the material and thickness of the thin plate 8 so that the generated plate wave 12 propagates in the thin plate 8 with as little energy loss as possible.
- the value of [frequency X plate thickness] ( ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ thigh) be approximately 10 or less.
- the height h of the P echo is a function of only the contact stress ⁇ when the width B of the solid 9 and the spacing between the probes 14 and 15, that is, the propagation distance of the plate wave, are constant, as described above. Since it has a relationship inversely proportional to the stress ⁇ , to obtain the contact stress ⁇ from the obtained echo height h, the empirical formula obtained in the experiment described later must be By programming, the method of calculating by inputting the length h of the P echo, or by inputting various values into the empirical formula, create a graph that combines the height h of the P echo with the contact stress. In advance, a method such as obtaining the contact stress ⁇ from the graph is used.
- FIGS. Fig. 4 is a side view explaining the experimental situation
- Fig. 5 is a view taken in the direction of arrows V-V in Fig. 4
- Fig. 6 is a graph showing the relationship between the contact stress and the echo length obtained in the experiment. It is. In the experiment, the thickness of the thin plate 8 was t!
- the frequency of the ultrasonic wave is 2 MHz
- the plate wave generated from the relationship with the thickness of the thin plate 8 of 1.2 mm is the so-mode of the symmetric wave (s-mode).
- the contact stress ⁇ is generated on the contact surface 4 ′ simultaneously with the contact surface 4 because the thin plate 8 is pressed from the rain surface by the load W.
- the horizontal axis of the figure is the contact stress ⁇ (kg / Dm 2 ), and the vertical axis is the echo height li (d B).
- the echo height h obtained in this case is such that the corrosion stress ⁇ , increases in proportion to the increase in the load W, and the wave restraint on the contact surfaces 4, 4 'is greatly reduced. It will be reduced.
- FIG. 3 shows a case where the transmitting probe 14 and the receiving probe 15 are both arranged on the thin plate 8 on the same side as the contact surface 4.
- the invention is not limited to such an embodiment. That is, FIG. 7 shows a case where the probes 14 and 15 are arranged on a surface opposite to the contact surface 4, and FIG. 8 shows a case where the probe 14 for transmission is opposite to the contact surface 4. Placed on the thin plate 8 on the side surface for receiving An example is shown in which the probe 15 is arranged on the thin plate 8 on the same side as the contact surface 4. The contact surfaces of the probes 14 and 15 in FIG. 8 may be reversed.
- the above-described method is a visual measurement method in which an echo is displayed on a CRT, but the amount of analog of the echo height is digitized by a commonly used means without displaying on the CRT, and the analog It is also possible to calculate the amount of data and to express it numerically. Also, by storing these in a storage device and comparing them with a reference value, it is possible to make a preventive diagnosis of equipment failure or to use it as basic data for automatic control.
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Abstract
This invention relates to a method of measuring contact stress on a contact surface of a thin sheet (mainly up 2 to 3 mm thick) in contact with other solid by utilizing a sheet wave available in one of the ultra-sonic modes. A probe is brought into contact with the thin sheet, an ultrasonic wave is projected to the thin sheet from the probe to generate the sheet wave, the resulting sheet wave is propagated through the thin sheet and passed through the contact surface and the contact stress is measured by use of the sound pressure of the passing sheet wave as an index of evaluation. It becomes thus possible to measure the contact stress between the thin sheet and other solid, which has been measured conventionally only by dipping the thin sheet into a liquid tank, without using the liquid tank, both statically and dynamically, quantitatively, rapidly and moreover on a real time basis.
Description
明 TO 超音波による接触応力測定方法 技 術 分 野 Akira TO Ultrasonic method for measuring contact stress
本発明は、 接触状態にある薄板と他の画体との接触面にお ける接触応力を、 超音波のモー ドのう ち扳波を利用 して測定 する方法に関する。 The present invention relates to a method for measuring a contact stress at a contact surface between a thin plate in contact with another object using an ultrasonic wave.
こ こ に云う薄板とは板波が伝搬され得る厚さ (主と して 2 〜 3 咖以下で約 l O nraまで) の薄い部材をいい、 その形状は帯 状, 板状等の平面形状はもちろん管材等の円筒形状、 曲面部 を有する部材の曲面形状をも包含する。 また、 接触状態にあ る薄板および他の固体は、 超音波が伝搬され得る金属および 非金属 (ガラス, セラ ミ ッ ク ス, 合成樹脂等) であっ て、 そ の接触状態は、 たとえばバン ドによ り固定された配管等の管 とバン ド と の接触, 薄肉管の端部を壁に設けた穴に拡径して 圧着した管敢付部の管と壁との接触等の静的な状態のほか、 前記接触面が搢動または滑動のよ う に相対的に変位する動的 な状態も含まれる。 The term “thin plate” as used herein refers to a thin member whose thickness (mainly 2 to 3 mm or less and up to about lonra) through which a plate wave can propagate, and whose shape is a band shape, plate shape, or other planar shape. Needless to say, it also includes a cylindrical shape such as a tube material and a curved shape of a member having a curved surface portion. The thin plates and other solids in contact are metals and non-metals (glass, ceramics, synthetic resin, etc.) through which ultrasonic waves can propagate, and the contact state is, for example, a band. The contact between the pipe and other fixed pipes and the band, and the contact between the thin walled pipe and the wall of the pipe at the end of the thin-walled pipe that has been expanded and crimped into the hole provided in the wall. In addition to the dynamic state, a dynamic state in which the contact surface is relatively displaced like sliding or sliding is also included.
背 景 技 術 Background technology
超音波を利用 して接触面の接触応力を測定する方法に関 し ては、 すでに同種または異種の固体接触面の接触応力を測定 する方法と して、 「超音波による固体接触面の接触応力測定 方法」 が提案されている。 (本願出顕人の出穎に係わる P C T / J P 82 / 00087 )
この方法は、 2つの固体の接触面に超音波を入射させ、 そ , の超音波の前記接触面から反射される反射波の音圧と接触面 を透過した透過波の音圧との双方を利用 し、 雨者を比較して その比較値を評価の指標と して前記接触面における接触応力 を測定するもので、 それまで測定し得なかった焼き嵌めされ た嵌合面やボルトによる締結面等における接触応力を、 定量 的かつ高精度に測定可能に したものである。 Regarding the method of measuring the contact stress of a contact surface using ultrasonic waves, as a method of measuring the contact stress of a solid contact surface of the same or different type, the `` Contact stress of a solid contact surface by ultrasonic waves '' is already used. Measurement method ”has been proposed. (PCT / JP 82/00087 related to the spleen of the presenter) In this method, ultrasonic waves are incident on two solid contact surfaces, and both the sound pressure of the reflected waves of the ultrasonic waves reflected from the contact surfaces and the sound pressure of the transmitted waves transmitted through the contact surfaces are measured. It is used to measure the contact stress on the contact surface using the comparison value as an evaluation index, comparing the rainy people, and the shrink-fitted fitting surface and the fastening surface with bolts that could not be measured until then This enables quantitative and high-precision measurement of contact stress in such applications.
第 9 図および第 10図は前記 P C T Z J P 82 Z 00087に記載 されている測定方法の代表的な実施例の説明図で、 第 9 図は 金属 (例えば機械構造用炭素鑲製のボス) に金属 Π (例え ば機械構造用炭素鎇錁管製のプッ シング) を圧入した場合の 嵌合面 (接触面) における接触応力を測定する例である。 図 において 1 はパルス反射式の超音波探傷装置、 2 は探触子 (この場合は垂直採触子) である。 金属 I の外表面に探触子 2 を当接し接触面 4 に対して超音波 3 (この場合縦波) をほ ぼ垂直に入射させると、 入射した超音波 3 は、 接触面 4 にて 反射する第 1反射波 6 と、 接触面 4 を透過して金属 II内へ入 リ金属 Πの底面でほぼ 100 %反射し再び接触面 4 を透過して 金属 I 内へ入る第 2反射波 7 と、 金属 Πの底面における反射 波が接蝕面 4 を透過せず接触面 4で反射して金属! [内で反射 を繰り返すものとに分かれる。 このう ち探触子 2 に受信され る第 1反射波 S は、 ·第 1 0図に示すよ う に超音波探傷装置 1 の C R T上に、 送信パルス 5 の位置よ リ金属 I の厚さ t t に対 応する時間 T t経過後の位置にエコー高さ h B lの エコーと して出現し、 第 2反射波 7 は、 同じ く送信パルス 5 の位置よ
リ金属 Πの厚さ t 2に対応する時間 Τ2経過後の位置にエコー 高さ h Plの Ρ エコーと して出現する。 出現した B iエコーの 高さ h Blと Piエコーの髙さ h Plとの比較値は、 次式 FIG. 9 and FIG. 10 are explanatory views of a typical embodiment of the measuring method described in PCTZJP 82 Z 00087. FIG. 9 is a diagram showing a method of using a metal (for example, a boss made of carbon steel for a mechanical structure). This is an example of measuring the contact stress on the mating surface (contact surface) when press-fitting (for example, a carbon steel pipe for machine structure). In the figure, 1 is a pulse reflection type ultrasonic flaw detector, and 2 is a probe (in this case, a vertical probe). When the probe 2 is brought into contact with the outer surface of the metal I and the ultrasonic wave 3 (in this case, a longitudinal wave) is made almost perpendicular to the contact surface 4, the incident ultrasonic wave 3 is reflected by the contact surface 4. The first reflected wave 6 that passes through the contact surface 4 and enters the metal II, and the second reflected wave 7 that passes through the contact surface 4 to enter the metal I after being almost 100% reflected at the bottom surface of the metal Π The reflected wave on the bottom surface of the metal Π does not transmit through the contact surface 4 but is reflected by the contact surface 4 and the metal! [It is divided into those that repeat reflection within. The first reflected wave S received by the probe 2 has the following thickness on the CRT of the ultrasonic flaw detector 1 at the position of the transmission pulse 5 as shown in Fig. 10 tt to appear as a echo corresponds to the time T t has elapsed echo height h B l to the position after the second reflected wave 7, the position of the same Ku transmission pulse 5 Appearing as a Ρ echo echo height h Pl to position after the time T 2 has elapsed, corresponding to the thickness t 2 of the Li metal [pi. The comparison value between the height h Bl of the appearing Bi echo and the length h Pl of the Pi echo is
Δ h ( d B ) = 20 fiog 1 (( )) Δ h (d B) = 20 fiog 1 (())
で求めるか、 またはエコー高さ をデシベル値で表示した場合 には エコーと Piエコーの高さの差に寄り Δ h ( d B )が求 められる。 接触応力は求めた比較値 A h を予め実験によ り確 認されている接触応力とエコー高さの差 A h との対数で直線 の相関関係を示す実験式に入れて; S十算するか、 実験式を計算 して作成したグラフによ リ求める。 Or when the echo height is expressed in decibels, Δh (dB) can be obtained depending on the difference between the echo height and the Pi echo height. For the contact stress, the comparative value A h obtained is put into an empirical formula that shows a linear correlation with the logarithm of the difference A h between the contact stress and the echo height, which is confirmed in advance by experiments; Or from a graph created by calculating empirical formulas.
P C T / J P 82 00087には、 接触面 4 から反射される反 射波の音庄と接触面 4 を透過した透過波の音圧と を比較する 具体的な方法と して上記第 9 図に示した方法のほか、 金属 I の外表面に送信用の垂直探触子を当接し金属 Π の底面に透過 波を受信する受信用の垂直探触子を配置し、 送信用の垂直探 触子で受信した接触面 4 からの反射波と受信用の垂直探触子 で受信した接触面 4 を透過した透過波と を比較する方法、 斜 角探触子を使用 し接触面 4 に対して斜角方向から超音波 (こ の場合 jl波) 入 _射し、 接触面 4 からの反射波および接触 面 4 を透過する透過波のいずれも斜角出射する超音波を斜角 探触子で受信して比較する方法、 および上記金属 I および Π の表面に探触子を直接接触させる方法とは異な り 、 被検体と 探触子と を間隔を設けた状態で液中に浸渍し、 該液体を介し て接触面 4 に超音波を入射させる、 いわゆる液浸法による方
法などが提案されている。 と こ ろでこれらの各測定方法は、 被測定物の寸法, 形状等によ り選択し使い分けられるのは匆 論であるが、 例えば被測定物に探触子を当接し得るか否か、 液槽内に被測定物を浸漬させられるか否かなど、 被測定物の 寸法, 形状のほか 測定物の周西の使用中の環境条件等によ リ適用の選択が制限され、 特に第 9 図における被測定物の厚 さ寸法 t 1 , t 2によっては測定可能の範囲が制限される。 す なわち接触応力を前記直接接触法によ り測定する場合には、 接触している固体 I と固体 Πの厚さ寸法が、 接触面 4 からの 反射波のェコ一と接触面 4 を透過した透過波のエコーと を明 暸に分離して測定できる程度の厚さである ことが必要になる。 それは例えば厚さ寸法が 2 〜 3 脆以下の薄い板材と他の固体 との接触面 4 を測定するよ う な場合には、 前記反射波と透過 波の雨エコーが明瞭に分離されないだけでなく 、 送信波とも 重な y測定する こ と ができないからで、 かかる場合には最小 探傷距離が短く また高い周波数の使用が容易で薄材の探傷が 可能な液浸法を適用 して測定する ことになる。 一方、 液浸法 による場合は板厚のほか前記被測定物の使用中の環境条件が 直接影響し、 液槽に浸漬できない場合は測定対象にする こ と ができない基本的な問題点があ り、 また当然のこ とであるが、 被測定物の寸法 ·, 形拔, 材質等に応じた浸渍可能の液槽の準 備が不可欠であ り、 同時に測定可能な範囲は準備可能な液槽 の大きさ に制限される。 したがって測定の対象は寸法的には 比較的小物部品に制限され、 液槽の準備の困難な稼動現場等 における機器の測定は事実上できないなどの制限を受ける t
また測定に当っては、 探触子と被測定物の探傷面との間隔を 一定に保持してスキャニングする必要があ り 、 装置の構造お よび測定が面倒にな リ、 簡易にかつ リ アルタ イムに測定する こと ができない問題点を有する。 さ らに前記各方法は、 直接 接触法および液浸法を間わず、 被測定物に接触面 4 を透過し た透過波が反射するための底面または透過波を受信するため に探触子を当接する底面が必要で、 かかる底面が接触面 4 に 対してかな り離れた位置にある場合や、 他の構造物と一体に 結合されていて事実上底面が得られない場合等には、 測定上 必要な反射波お.よび透過波が得られな く な り測定できない場 合がある。 PCT / JP 82 00087 shows a specific method for comparing the sound level of the reflected wave reflected from the contact surface 4 with the sound pressure of the transmitted wave transmitted through the contact surface 4 as shown in FIG. 9 above. In addition to the method described above, a vertical probe for transmission abuts on the outer surface of Metal I, and a vertical probe for reception to receive transmitted waves is placed on the bottom of Metal Π. A method for comparing the reflected wave from the contact surface 4 received with the transmitted wave transmitted through the contact surface 4 received by the vertical probe for reception, using the oblique probe to bevel to the contact surface 4 Ultrasonic waves (in this case, jl waves) are input and emitted from the direction, and both the reflected waves from the contact surface 4 and the transmitted waves transmitted through the contact surface 4 receive the ultrasonic waves emitted at an oblique angle with the oblique probe. The method differs from the method in which the probe is in direct contact with the surface of metal I and 上 記, and the distance between the subject and the probe is different. And Hita渍 in providing state in the solution, is incident ultrasonic waves to the contact surface 4 through the liquid, it so-called immersion method Laws and the like have been proposed. It is a theory that each of these measurement methods can be selected and used depending on the size, shape, etc. of the object to be measured. For example, whether or not the probe can be brought into contact with the object to be measured is determined. The choice of application is limited by the dimensions and shape of the object, such as whether or not the object can be immersed in the liquid tank, and the environmental conditions in use around the circumference of the object. The measurable range is limited depending on the thickness t 1 and t 2 of the DUT in the figure. In other words, when the contact stress is measured by the direct contact method described above, the thickness dimension of the solid I and the solid Π in contact is determined by the difference between the echo of the reflected wave from the contact surface 4 and the contact surface 4. It is necessary that the thickness be such that the transmitted transmitted echo and the transmitted wave can be clearly separated and measured. For example, when measuring the contact surface 4 between a thin plate having a thickness of 2 to 3 brittle or less and another solid, not only the rain echo of the reflected wave and the transmitted wave are not clearly separated, but also Since it is not possible to perform y measurement that overlaps with the transmitted wave, in such a case, use a liquid immersion method that has a short minimum flaw detection distance, is easy to use at high frequencies, and allows flaw detection of thin materials. become. On the other hand, in the case of the immersion method, there is a basic problem that, in addition to the plate thickness, the environmental conditions during use of the object to be measured directly affect the measurement object if the object cannot be immersed in the liquid tank. As a matter of course, it is essential to prepare an immersible liquid tank in accordance with the dimensions, shape, material, etc. of the object to be measured. It is limited to the size of. Therefore the object of measurement is limited to relatively small components to scale, the measurement equipment in difficult working sites like the preparation of the liquid bath is restricted, such as practically impossible t In measurement, it is necessary to maintain the distance between the probe and the flaw detection surface of the object to be measured at a constant level for scanning, which makes the structure and measurement of the device complicated, simple, and real-time. There is a problem that cannot be measured immediately. Further, in each of the above methods, the direct contact method and the liquid immersion method are not used, and the bottom surface for reflecting the transmitted wave transmitted through the contact surface 4 on the object to be measured or the probe for receiving the transmitted wave is used. When the bottom surface is required to be in contact with the contact surface 4 and the bottom surface is far away from the contact surface 4, or when the bottom surface is not obtained because it is integrated with other structures, etc. In some cases, reflected waves and transmitted waves required for measurement cannot be obtained and measurement may not be possible.
本発明は、 上記した従来技術の問題点を解消 して、 被測定 接触面の接触状態および性質を変化させる こ とな く定量的か つ短時間に しかも リ アルタ イムに評価する こ と ができる超音 波による薄板と他の固体との接触面の接触応力測定方法を提 供する こ と を基本的な目的とする。 The present invention solves the above-mentioned problems of the prior art, and enables a quantitative, short-time and real-time evaluation without changing the contact state and properties of the contact surface to be measured. It is a basic object of the present invention to provide a method for measuring the contact stress of a contact surface between a thin plate and another solid by ultrasonic waves.
また、 本発明の他の 目的は、 被測定接触面における接触応 力の分布状態の測定および摺動または回動状態の被測定接触 面における動的な接触応力のモニタ リ ングを、 連続的に行う こ とができる超音波による薄板と他の固体との接触面の接触 応力測定方法を提供する こ と にある。 Another object of the present invention is to continuously measure the distribution of the contact stress on the contact surface to be measured and to monitor the dynamic contact stress on the contact surface to be measured in a sliding or rotating state. An object of the present invention is to provide a method for measuring contact stress of a contact surface between a thin plate and another solid by using ultrasonic waves.
本発明のさ らに他の 目的は、 以下の説明および図面の参照 によ リ明 ら.かになるであろう Still other objects of the present invention will become apparent with reference to the following description and drawings.
発 明 の 開 示 Disclosure of the invention
本発明は、 接触している薄板と他の固体のう ち薄板に探触
子を当接し、 該探触子よ り薄板に超音波を入射して板波を発 生させ、 発生した板波を前記薄板を伝搬させて接触面を通過 させ、 その通過した板波の音圧を評価の指標と して接触面に おける接触応力を測定する こと を特徴とする。 The present invention detects thin plates in contact with other thin plates The probe makes contact with the probe, ultrasonic waves are incident on the thin plate from the probe to generate a plate wave, and the generated plate wave propagates through the thin plate and passes through the contact surface. It is characterized by measuring the contact stress at the contact surface using the pressure as an evaluation index.
本発明の特徵は、 薄板と他の固体との接触面における接触 応力と該接触面を通過して受信された板波の音圧との間に一 定の相関関係がある性質を利用するもので、 以下第 1 図およ び第 2図を参照して説明する。 図において 8 は薄板である。 図に示す幅 B の接触面 4 に、 接触応力 び が発生している状態 で入射点 10よ り薄板 8 に横波を入射する と、 一定の条件、 す なおち入射した横波の周波数一薄板 8 の板厚一ポアソン比の 間の関係によ り決まるモードの板波が薄板 8 に発生する。 発 生した板波 12は薄板 8 を伝搬し接触面 4 を通過した後入射点 10ょ リ間隔 β だけ離れた出射点 11よ り出射するが、 出射点 11 における板波 12は、 接触面 4 を通過中に接触応力 σ の影響を 受けてその波動が拘束され、 また同時に接触面 4 を介して他 の固体に伝搬して拡散されるため減衰された板波 13と して出 射する。 この板波 12の減衰は、 入射点 10から出射点 11までの 間隔 β つま リ扳波の伝搬距離における薄板 8 の外表面からの 扳波エネルギの放射によっても生ずる。 板波 13の受信エコー を C R T上に表^する と第 2 図に示すよ う なエコーパターン となる。 すなわち原点の送信パルス Tの位置よ リ前記間隔 β に対応する時間 t 経過後の位置にエコー高さ h の Pェコ一と して出現する。 A feature of the present invention is to utilize a property that has a certain correlation between contact stress at a contact surface between a thin plate and another solid and sound pressure of a plate wave received through the contact surface. A description will be given below with reference to FIGS. 1 and 2. In the figure, 8 is a thin plate. When a shear wave is applied to the thin plate 8 from the point of incidence 10 in the state where contact stress and stress are generated on the contact surface 4 of width B shown in the figure, under certain conditions, that is, the frequency of the incident transverse wave minus the thin plate 8 A sheet wave of a mode determined by the relationship between the sheet thickness and the Poisson's ratio is generated in the thin plate 8. The generated plate wave 12 propagates through the thin plate 8, passes through the contact surface 4, and then emerges from the exit point 11, which is separated from the incident point 10 by an interval β, but the plate wave 12 at the exit point 11 is While passing through, the wave is constrained under the influence of the contact stress σ, and at the same time, propagates through the contact surface 4 to other solids and is diffused and emitted as an attenuated plate wave 13. The attenuation of the plate wave 12 is also caused by the radiation of the microwave energy from the outer surface of the thin plate 8 at the distance β from the incident point 10 to the output point 11, that is, the propagation distance of the wave. When the received echo of the plate wave 13 is represented on the CRT, an echo pattern as shown in FIG. 2 is obtained. That is, it appears as a P echo having an echo height h at a position after the elapse of the time t corresponding to the interval β from the position of the transmission pulse T at the origin.
Pエコーの高さ h は、 前記の如く 、 接触応力 ぴ が大き く な
るにつれて接舳面 4 における波動の拘束が高ま り, その拘束 の高ま り に比例して滅衰が大き く なる関係にあ り、 また接触 面 4 の幅 B は大き く なるにつれて該接触面を介して他の固体 側へ伝瘢し拡散する板波が増加し滅衰量が大き く なる関係を 有しており、 さ らに入射点 1 0と出射点 1 1の間隔 β が大き く な ると薄板 8の外表面から伝搬中の板波のエネルギ放射の量が 多く な リ それに比例して減衰量が大き く なる関係を有する。 このよ う に Ρエコーの高さ h は接触応力 ひ , 接触面 4 の幅 B および板波の伝搬距離 ώ の関数であ り、 これらの関係は次の 関係式で表わされる。 h 0< σ . B ■ . ·'· ··■ '·· ( 1 ) As described above, the height h of the P echo is such that the contact stress ぴ is large. As the height of the constraint increases, the wave constraint on the bow 4 increases, and the decay increases in proportion to the height of the constraint. As the width B of the contact surface 4 increases, the width of the contact increases. There is a relationship that the plate wave that spreads and spreads to the other solid side through the surface increases and the amount of decay increases, and the interval β between the entrance point 10 and the exit point 11 is large. When it becomes smaller, the amount of energy radiation of the plate wave propagating from the outer surface of the thin plate 8 increases, and the attenuation increases in proportion to the amount. Thus, Ρthe height h of the echo is a function of the contact stress h, the width B of the contact surface 4 and the propagation distance of the plate wave 、, and these relationships are expressed by the following relational expressions. h 0 <σ. B ■. · '· ·· ■' ·· (1)
上式(1 )は受信エコー ( Ρエコー) の高さ h が、 接触応力 σ, 接触面 4の幅 Β および板波の伝搬距離 β の積に逆比例する こ と を示しているが、 このうち接触面 4 の幅 Β および板波の伝 搬距離 β は被測定物が特定されれば一定となるため、 受信ェ コ一の高さ h は接触応力 σ のみの関数にな り、 次のよ う に簡 単な闋係式になる。 h oc - ( 2 ) The above equation (1) shows that the height h of the received echo (Ρecho) is inversely proportional to the product of the contact stress σ, the width of the contact surface 4 Β, and the propagation distance of the plate wave β. Of these, the width 接触 of the contact surface 4 and the propagation distance β of the plate wave are constant once the DUT is specified, so the height h of the receiving echo is a function of only the contact stress σ, and It becomes a simple engagement equation. h oc-(2)
σ 本発明の測定方法は、 上記式(2 )の関係、 つま り受信ェコ '一の髙さ h が接触応力 σ に逆比例する関係を利用するもので ある。 この受信エコーの高さ h と接触応力 σ との関係は、 後 述する実験において対数で直線の関係を有する こ と が検証さ れており、 従って、 接触応力 σ の発生している状態のまま被
被測定物の受信エコーの高さ h を測定するた'けで接触応力 σ を定量的に評価するこ と ができ、 従来技術における液浸法に よ り接触面からの反射波音圧と接触面を透過した透過波の音 圧とを比較して評価する場合に比べて、 薄板と他の固体との 接触面における接触応力を被測定物を浸漬する液槽を使用す る こ とな く 容易に、 しかも リ アルタ イムに評価する こ と がで きる特徵を有している。 σ The measuring method of the present invention utilizes the relationship of the above equation (2), that is, the relationship in which the length h of the reception echo is inversely proportional to the contact stress σ. The relationship between the height h of the received echo and the contact stress σ has been verified to have a logarithmic linear relationship in an experiment described later, and therefore, the state where the contact stress σ is generated Suffered The contact stress σ can be quantitatively evaluated simply by measuring the height h of the received echo of the DUT, and the sound pressure reflected from the contact surface and the contact surface The contact stress at the contact surface between the thin plate and the other solid is easier than using a liquid bath in which the object is immersed, as compared with the case of evaluating by comparing the sound pressure of the transmitted wave transmitted through the object. In addition, it has features that can be evaluated in real time.
また、 本発明の測定方法は、 接触応力 σ が第 1図に示す接 触面 4の幅 Β と直角方向に広い幅にわたリ発生しているよ う な場合には、 入射点 10および出射点 1 1を間隔 J2 を保持したま ま前記直角方向に移動する こ と によ り、 接触応力 σ の分布状 態を連続的に測定することができる特徵を有している。 なお これは、 入射点 10および出射点 1 1を前記直角方向に複数個所 並設し、 同時またば頗次に測定するよ う に してもよい。 Further, when the contact stress σ is generated over a wide width in a direction perpendicular to the width の of the contact surface 4 shown in FIG. By moving the point 11 in the right-angle direction while maintaining the interval J2, the distribution state of the contact stress σ can be continuously measured. In this case, a plurality of incident points 10 and outgoing points 11 may be juxtaposed in the right-angle direction, and measurement may be performed simultaneously or extremely.
さ らに本発明の測定方法は、 たとえば薄肉円筒とその外周 を回動する回転体のよう に薄板 8 と他の固体 9 が缙動または 滑動状態にあ リ、 接触応力 <? が動的に変化するような場合に おいては、 入射点 10および出射点 1 1を一定位置に設定するこ とによ り接触応力 σ の変化状態を連続的にモニタ リ ングして 測定する こと ができる特徵を有している。 In addition, the measurement method of the present invention is based on the assumption that the thin plate 8 and the other solid 9 are in a sliding or sliding state, such as a thin-walled cylinder and a rotating body rotating around its outer periphery, and the contact stress <? In such a case, by changing the incident point 10 and the exit point 11 to fixed positions, the state of change of the contact stress σ can be continuously monitored and measured. have.
前記接触面 4 を通過した板波の音圧 (エコー高さ) を測定 する方法と しては 3通り ある。 すなわち、 1 は接触面 4 と同 じ側の面の薄扳上に送信用および受信用の両探触子を配置す る方法、 2 は、 接触面 4 と反対側の面の薄板上に送信用およ び受信用の雨探触子を配置する方法、 3 は、 接触面 4 と同じ
g There are three methods for measuring the sound pressure (echo height) of a plate wave passing through the contact surface 4. That is, 1 is a method of arranging both transmitting and receiving probes on the same thin plate on the same side as the contact surface 4, and 2 is a method of sending both probes on the thin plate on the opposite surface to the contact surface 4. How to place rain probes for credit and reception, 3 is the same as contact surface 4 g
側の面の薄板上に送信用 (または受信用) の探触子を配置し、 接触面 4 と反対側の面の薄板上に受信用 (または送信用) の 探触子を配置する方法である。 これら 1 , 2, 3 の各方法は、 探触子の配置が接触面 4 と相対的に異なるものの、 伝搬距離 β を同じに配置すれば得られる板波の音圧は同一であ り、 接 触面 4 の周辺の状況に応じていずれかの方法を選択して使用 する ことができる。 A transmitting (or receiving) probe is placed on the thin plate on the side, and a receiving (or transmitting) probe is placed on the thin plate on the side opposite to the contact surface 4. is there. In each of these methods 1, 2, and 3, although the arrangement of the probe is relatively different from that of the contact surface 4, the sound pressure of the plate wave obtained when the propagation distance β is the same is the same, and the contact Either method can be selected and used according to the situation around the touch surface 4.
図面の簡単な説明 BRIEF DESCRIPTION OF THE FIGURES
第 1 図は本発明の測定方法の原理説明図、 第 2図は第 1 図 の方法によ り得られた受信エコーの C R T上のエコーパター ンの説明図である。 FIG. 1 is an explanatory view of the principle of the measuring method of the present invention, and FIG. 2 is an explanatory view of an echo pattern on a CRT of a received echo obtained by the method of FIG.
第 3 図は本発明の実施例の概要説明図、 第 4 図は本発明の 測定方法の効果を検証するために行なっ た実験の概要説明図、 第 5 図は第 4 図の V— V矢視図、 第 6 図は第 4 図に示す実験 の結果で接触応力とエコー高さ との関係を示すグラ フである。 FIG. 3 is a schematic explanatory diagram of an embodiment of the present invention, FIG. 4 is a schematic explanatory diagram of an experiment conducted to verify the effect of the measurement method of the present invention, and FIG. 5 is a VV arrow of FIG. Fig. 6 is a graph showing the relationship between contact stress and echo height based on the results of the experiment shown in Fig. 4.
第 7図および第 8 図は本発明の測定方法の他の実施例を示 すもので第 3 図と同様の概要説明図である。 7 and 8 show another embodiment of the measuring method of the present invention, and are schematic explanatory diagrams similar to FIG.
第 9 図は従来の超音波を利用 した固体接触面の接触応力の 測定方法の例で P C T / J P 82 Z 00087に記載されている説 明図、 第 10図は第 9 図に示す方法によ リ得られた C R T上の エコーパターンを示す説明図である。 発明を実施するための最良の形態 FIG. 9 is an example of a conventional method for measuring the contact stress of a solid contact surface using ultrasonic waves, and is an explanatory diagram described in PCT / JP 82 Z 00087. FIG. 4 is an explanatory diagram showing an echo pattern on a CRT obtained. BEST MODE FOR CARRYING OUT THE INVENTION
本発明の好ま しい実施例を以下第 3 図を参照して説明する。 第 3 図において、 8 は薄板 (たとえば薄肉の管) 、 9 は薄 板 8 と接触面 4で接触している幅 B の固体 (たとえば管を固
定するバン ド) で、 接蝕面 4 が押圧されて檑 B に接触応力 σ が発生している。 14は薄板 8 に板波 (この場合はラム波) 12 を励振させる送信用の探触子、 15は接蝕面 4 をはさみ探触子 14と相対して薄板 8上に間隔 β で当接している受信用の探触 子である。 A preferred embodiment of the present invention will now be described with reference to FIG. In FIG. 3, reference numeral 8 denotes a thin plate (for example, a thin tube), and 9 denotes a solid having a width B in contact with the thin plate 8 at the contact surface 4 (for example, the tube is solidified). In this case, the contact surface 4 is pressed and a contact stress σ is generated at に B. 14 is a transmitting probe for exciting a plate wave (in this case, a Lamb wave) 12 on the thin plate 8, 15 is a pair of scissoring surfaces 4, and abutting the probe 14 against the thin plate 8 at an interval β. This is the receiving probe.
いま探蝕子 14よ りそのく さびを介して入射点 10から薄板 8 に横波を入射する。 この場合薄板 8 には入射した横波の周波 数一薄板 8 の板厚一薄扳 8 のポアソン比の間の関係で決まる · モードの板波 12が発生する。 発生した扳波 12は薄板 8 を伝擬 し途中接触面 4 を通過して出射点 11に達し探蝕子 15に受信さ れるが、 受信される板波 13は接触面 4 の影響を受けて減衰す るため、 発生した板.波 12が薄扳 8内をできるだけ少ないエネ ルギ損で伝搬するよう に、 薄扳 8 の材質および扳厚に応じて 周波数を選定する。 そして本発明の対象とする薄板 (主と し て厚さ 2〜 3 腿以下) の場合、 〔周波数 X板厚〕 (Μ Η ζ Χ 腿) の値は、 ほぼ 10以下とする ことが好ま しい。 探触子 13に 受信された板波 13の受信エコーは、 超音波探傷装置 1の C R T l aに原点の送信パルス Τよ リ探触子 14, 15の設置間隔 J¾ に対応する時間 t経過後の位置に、 エコー高さ h の Pエコー と して出現し槿め T簡単に—得 ¾れる。 Now, a transverse wave is incident on the thin plate 8 from the incident point 10 through the wedge of the probe 14. In this case, a mode plate wave 12 is generated in the thin plate 8, which is determined by the relationship between the frequency of the incident transverse wave and the thickness of the thin plate 8 minus the Poisson's ratio of the thin plate 8. The generated wave 12 simulates the thin plate 8, passes through the contact surface 4 on the way, reaches the emission point 11 and is received by the probe 15, but the received plate wave 13 is affected by the contact surface 4. In order to attenuate, the frequency is selected according to the material and thickness of the thin plate 8 so that the generated plate wave 12 propagates in the thin plate 8 with as little energy loss as possible. Then, in the case of a thin plate (mainly a thickness of 2 to 3 thighs or less) targeted by the present invention, it is preferable that the value of [frequency X plate thickness] (ζ Η ζ と す る thigh) be approximately 10 or less. . The received echo of the plate wave 13 received by the probe 13 is transmitted to the CRT la of the ultrasonic flaw detector 1 after the time t corresponding to the installation interval J¾ between the probes 14 and 15 At the position, it appears as a P echo with an echo height h, and is easily obtained.
Pエコーの高さ h は、 前記の如 く 固体 9 の幅 Bおよび探触 子 14, 15の設置間隔すなわち板波の伝搬距離 が一定の場合 は、 接触応力 σ のみの関数とな り、 接触応力 σ に逆比例する 関係を有するから、 得られた Ρエコーの高さ h から接触応力 σ を求めるには、 後述の実験によ り求めた実験式を電卓等に
プログラムしておき、 前記 Pエコーの髙さ h を入力して計算 させる方法や、 実験式に種々の値を入力 し Pエコーの高さ h と接触応力 び との相閧するグラ フを作成しておき、 そのグラ フよ り接触応力 σ を求める等の方法を使用する。 The height h of the P echo is a function of only the contact stress σ when the width B of the solid 9 and the spacing between the probes 14 and 15, that is, the propagation distance of the plate wave, are constant, as described above. Since it has a relationship inversely proportional to the stress σ, to obtain the contact stress σ from the obtained echo height h, the empirical formula obtained in the experiment described later must be By programming, the method of calculating by inputting the length h of the P echo, or by inputting various values into the empirical formula, create a graph that combines the height h of the P echo with the contact stress. In advance, a method such as obtaining the contact stress σ from the graph is used.
本発明の具 的な効果は次に述べる実験によ リ検証されて いる。 これを第 4 図ない し第 6図によ り説明する。 第 4 図は 実験状況を説明する側面図、 第 5図は第 4 図の V— V矢視図、 第 6図は実験によ り得られた接触応力とエコー髙さ との関係 を示すグラ フである。 実験は、 薄板 8 に板厚 t! = 1.2画 X幅 I - 50醒の蒂鑲 ( J I S G 3141冷間圧延鑲板 2種 S P C D - 2 ) を使用し、 他の固体 9 に厚さ t 2 = 10nm X幅 b 2 = 10mn X長さ (幅 I に同じ) = 50咖の棒銷 ( J I S G 4051機械構 造用炭素銷 S 35 C ) を使用 し、 アムスラ一形万能試験機によ リ固体 9上に荷重 Wを作用させて接触面 4 に接触応力 σ を発 生させ、 その接触応力 び を変化させながら固体 9 を間に して 薄板 8上に相対させて配置した 1対の送信用の探触子 14と受 信用の探触子 15との間に超音波を送受させて行なっ た。 この 場合の超音波 (横波) の周波数は 2 M Hzで、 薄板 8 の板厚 1.2咖との関係から発生する板波は対称波 ( S モー ド) のう ち S oモー ドである。 第 4 図の探触子 14, 15の設置間隔 (板 波の伝搬距離) ώ = 50腿の間は、 この S Qモー ドの板波が伝 搬している様子を模式的に示したものである。 またこの場合 の接触応力 σ は、 薄板 8 を雨面から荷重 Wで押圧する こ と に なるため接触面 4 と同時に接触面 4 'にも発生する。 The specific effects of the present invention have been verified by experiments described below. This will be described with reference to FIGS. Fig. 4 is a side view explaining the experimental situation, Fig. 5 is a view taken in the direction of arrows V-V in Fig. 4, and Fig. 6 is a graph showing the relationship between the contact stress and the echo length obtained in the experiment. It is. In the experiment, the thickness of the thin plate 8 was t! = 1.2 images X width I-50 Awakening 鑲 鑲 (JISG 3141 cold rolled slab type 2 SPCD-2), thickness t 2 = 10 nm X width b 2 = 10 mn X length on other solid 9 (Same as width I) = Using a bar sales of 50mm (JISG 4051 carbon sales S35C for machine structure), apply a load W on the solids 9 by the Amsla universal testing machine using a universal testing machine. 4 generates a contact stress σ, and while changing the contact stress and, a pair of transmitting probe 14 and a pair of transmitting probe 14 This was performed by transmitting and receiving ultrasonic waves to and from the child 15. In this case, the frequency of the ultrasonic wave (transverse wave) is 2 MHz, and the plate wave generated from the relationship with the thickness of the thin plate 8 of 1.2 mm is the so-mode of the symmetric wave (s-mode). Figure 4 of the probe 14, 15 installation interval (propagation distance of Lamb wave) of ώ = 50 thigh during the one Lamb wave in this S Q mode is showing how are propagated schematically It is. In this case, the contact stress σ is generated on the contact surface 4 ′ simultaneously with the contact surface 4 because the thin plate 8 is pressed from the rain surface by the load W.
まず最初に荷重 W = 0 の状態、 すなわち接触応力 σ = 0 の
状態で受信した探触子 15からの受信エコー高さ を求め、 つい でそれを基準と して煩次荷重 Wの値を増しながらそのときの 各エコー高さ を求めてプロ ッ ト して行く 。 この測定を測定点 n = 38について行った結果が第 6図で、 図の横軸は接触応力 σ ( kg / Dm 2 ) 、 縦軸はエコー高さ li ( d B ) である。 この 場合に得られるエコー高さ hは、 荷重 Wの増加に比例して接 蝕応力 σ,が髙く なるとともに、 接触面 4 , 4 'における波動 の拘束が大となリ减衰して次第に低下したものとなる。 なお 接触応力 σ は、 荷重 Wを探触面 4 または 4 'の面積で除した 値、 つま り接触面積にお る平均値が得られる。 図中 Ο印で プロッ 卜 した実験値を最小 2乗法にて回帰式を求めると、 h = - 29 fiog σ - 9 . 2 (3 ) First, when the load W = 0, that is, when the contact stress σ = 0 The height of the received echo from the probe 15 received in the state is obtained, and then the height of the disturbing load W is increased based on the height, and the height of each echo at that time is obtained and plotted. . FIG. 6 shows the result of performing this measurement for the measurement point n = 38. The horizontal axis of the figure is the contact stress σ (kg / Dm 2 ), and the vertical axis is the echo height li (d B). The echo height h obtained in this case is such that the corrosion stress σ, increases in proportion to the increase in the load W, and the wave restraint on the contact surfaces 4, 4 'is greatly reduced. It will be reduced. For the contact stress σ, the value obtained by dividing the load W by the area of the probe surface 4 or 4 ', that is, the average value in the contact area is obtained. When the regression equation is obtained by the least squares method using the experimental values plotted with Ο in the figure, h = -29 fiog σ -9.2 (3)
とな り、 第 6図に示す直線となる。 本実験によ り接触応力 σ と接触面 4 または 4 'を通過した板波の受信エコー高さ h と の間には、 第 6図に示すよう 対数で直線の相関関係の成立 する ことが検証され、 従ってこの回帰式または回帰式を用い て計算したグラ フによ り、 前記受信エコー高さ h を測定する だけで直ちに接触応力 σ を精度よ く定量的に しかも リアルタ ィムに求める ことができる。 Thus, the straight line shown in FIG. 6 is obtained. In this experiment, it was verified that a logarithmic linear correlation was established between the contact stress σ and the height h of the received echo of a plate wave passing through the contact surface 4 or 4 'as shown in Fig. 6. Therefore, by using the regression equation or a graph calculated using the regression equation, the contact stress σ can be determined accurately, quantitatively, and in real time by simply measuring the reception echo height h. it can.
前記第 3図に示す実施例は、 送信用の探触子 14および受信 甩の探触子 15を ともに接触面 4 と同じ側の面の薄板 8上に配 置した場合を示したが、 本発明はかかる実施例に限定される ものではない。 すな.わち、 第 7 図は、 探触子 14, 15を接触面 4 と反対側の面に配置した場合を示し、 第 8図は送信用の探 蝕子 14を接触面 4 と反対側の面の薄板 8上に配置し、 受信用
の探触子 15を接触面 4 と同じ側の面の薄板 8上に配置した場 合の例を示す。 第 8図の探触子 14と探触子 15の配置は当接面 を反対に してもよい。 The embodiment shown in FIG. 3 shows a case where the transmitting probe 14 and the receiving probe 15 are both arranged on the thin plate 8 on the same side as the contact surface 4. The invention is not limited to such an embodiment. That is, FIG. 7 shows a case where the probes 14 and 15 are arranged on a surface opposite to the contact surface 4, and FIG. 8 shows a case where the probe 14 for transmission is opposite to the contact surface 4. Placed on the thin plate 8 on the side surface for receiving An example is shown in which the probe 15 is arranged on the thin plate 8 on the same side as the contact surface 4. The contact surfaces of the probes 14 and 15 in FIG. 8 may be reversed.
前記第 7図および第 8図の実施例は、 接触面 4 と同 じ側の 面に探触子 14, 15を一定の間隔 £ で配置する こ とができない 場合、 例えば、 探触子の当接位置に何等かの障害物が張り 出 していて当接する こ とができない場合などに便利に使用する ことができる。 各実施例における探触子 14および 15と接触面 4 との間隔 β!, £ 2は、 等寸法すなわち £ / 2 にする必要は なく 、 任意であ り また間隔 ώ はたとえば探触子 14, 15が接触 面 4 を通過した板波を C R T上に受信できるよ う に配置され た寸法であればよい。 さ らに前記第 4 図、 第 7図および第 8 図はいずれも Sモー ドの板波が伝搬している様子を模式的に 示したが、 斜対称波 (Aモー ド) の場合でも測定は同一であ る。 In the embodiment shown in FIGS. 7 and 8, if the probes 14 and 15 cannot be arranged at a fixed distance £ on the same surface as the contact surface 4, for example, This can be used conveniently when some obstacles are protruding at the contact position and cannot be touched. Distance β between probes 14 and 15 and contact surface 4 in each embodiment β! , £ 2 need not be of equal dimensions, ie, £ / 2, but are arbitrary, and the spacing ώ is such that, for example, the probes 14, 15 can receive a plate wave passing through the contact surface 4 on the CRT. It is sufficient if the dimensions are arranged. Furthermore, Figs. 4, 7, and 8 above all show schematically the propagation of the S-mode plate wave, but the measurement was performed even for the obliquely symmetric wave (A-mode). Are the same.
以上説明した方法は、 C R T上にエコーを表示した目視に よる測定方法であるが、 C R T上に表示しないでエコー高さ のアナロ グ量を通常慣用されている手段によ りデジタル化し、 前記アナロ グ量を計算させて数値化して表わすこ とも可能で ある。 また、 これら を記憶装置に記憶させ、 基準値と比較さ せる こ と によ り機器の故障の予防診断を させた り、 自動制御 の基礎データ と して利用する こ とも可能である。 The above-described method is a visual measurement method in which an echo is displayed on a CRT, but the amount of analog of the echo height is digitized by a commonly used means without displaying on the CRT, and the analog It is also possible to calculate the amount of data and to express it numerically. Also, by storing these in a storage device and comparing them with a reference value, it is possible to make a preventive diagnosis of equipment failure or to use it as basic data for automatic control.
なお、 当然のこ とであるが、 本発明は前記の好ま しい実施 例に限定されるものではな く 、 本発明の技術的思想の範囲内 において種々変更し得る こ と は勿論である。
Needless to say, the present invention is not limited to the preferred embodiments described above, and can be variously modified within the technical idea of the present invention.
Claims
38 38
14 14
請 求 の 範 囲 . 薄板と他の固体との接触面における接触応力の測定方法 であって、 前記薄板に探 子を当接し、 該探触子よ リ薄板 に超音波を入射して钣波を発生させ、 発生した板波を前記 薄板を伝搬させて接触面を通過させ、 その通過した板波の 音圧を評価指標と して接触応力を測定する方法。 A method for measuring a contact stress at a contact surface between a thin plate and another solid, wherein a probe is brought into contact with the thin plate, and ultrasonic waves are incident on the thin plate from the probe to cause a wave. A method in which the generated plate wave is propagated through the thin plate to pass through the contact surface, and the contact stress is measured using the sound pressure of the passed plate wave as an evaluation index.
. 請求の範西 1 に従う薄板と他の固体との接触面における 接触応力の測定方法であって、 前記薄板に送信用の探触子 と受信用の探触子と を前記接触面の雨側に相对させて当接 し、 送信用の探触子よ り薄板に超音波を入射して板波を発 生させ、 発生した扳波を前記薄板を伝搬させて接触面を通 過させ、 その通過した板波を受信用の探触子に受信させ、 受信した板波の音圧を評価指標と して接触応力を測定する 方法。A method for measuring contact stress at a contact surface between a thin plate and another solid according to claim 1, wherein a transmitting probe and a receiving probe are attached to the thin plate on the rain side of the contact surface. The ultrasonic wave enters the thin plate from the transmitting probe to generate a plate wave, and the generated wave propagates through the thin plate and passes through the contact surface. A method in which a passing probe is received by a receiving probe, and the contact stress is measured using the sound pressure of the received plate wave as an evaluation index.
. 請求の範囲 2 に従う薄板と他の固体との接触面における 接触応力の測定方法であって、 前記薄板に送信用の探触子 と受信用の採触子とを前記接触面の-両側でかつ接触面と同 じ側の面に相対させて当接し、 送信用の探触子よ リ薄扳に 超音波を入射して板波を発生させ、 発生した扳波を前記薄 扳を伝搬させて接触面を通過させ、 その通過した扳波を受 信用の探触子に受信させ、 受信した板波の音圧を評価指標 と して接触応力を測定する方法。 . A method for measuring contact stress at a contact surface between a thin plate and another solid according to claim 2, wherein a transmitting probe and a receiving probe are attached to the thin plate on both sides of the contact surface. In addition, the probe is brought into contact with the surface on the same side as the contact surface, and ultrasonic waves are incident on the transmission probe in a thin manner to generate a plate wave, and the generated wave is propagated through the thin film. A method of measuring the contact stress using the sound pressure of the received plate wave as an evaluation index by passing the transmitted wave through the contact surface and receiving it through the receiving probe. .
. 請求の範囲 2 に従う薄板と他の固体との接触面における 接触応力の測定方法であって、 前記薄扳に送信用の探触子
138 A method for measuring contact stress at a contact surface between a thin plate and another solid according to claim 2, wherein the transmitting probe is provided on the thin plate. 138
15 Fifteen
と受信用の探触子と を前記接触面の両側でかつ接触面と反 封側の面に相対させて当接し、 送信用の探触子よ り薄板に 超音波を入射して板波を発生させ、 発生した板波を前記薄 板を伝搬させて接触面を通過させ、 その通過した板波を受 信用の探触子に受信させ、 受信した板波の音圧を評価指標 と して接触応力を測定する方法。 And the receiving probe are brought into contact with both sides of the contact surface and opposed to the contact surface and the sealing surface, and ultrasonic waves are incident on the thin plate from the transmitting probe to generate a plate wave. The generated plate wave propagates through the thin plate and passes through the contact surface, and the passed plate wave is received by the receiving probe, and the sound pressure of the received plate wave is used as an evaluation index. A method for measuring contact stress.
. 請求の範囲 2 に従う薄板と'他の固体との接触面における 接触応力の測定方法であって、 前記薄板に送信用の探触子 と受信用の探触子と を前記接触面の雨側でかつ接触面に同 じ側の面と反対側の面と に分けて相対させて当接し、 送信 用の探触子よ り薄板に超音波を入射して板波を発生させ、 発生した板波を前記薄板を伝搬させて接触面を通過させ、 その通過した板波を受信用の探触子に受信させ、 受信した 板波の音圧を評価指標と して接触応力を測定する方法。
A method of measuring contact stress at a contact surface between a thin plate and another solid according to claim 2, wherein a transmitting probe and a receiving probe are attached to the thin plate on the rain side of the contact surface. And the contact surface is divided into the same side and the opposite side and abutted against each other, ultrasonic waves are incident on the thin plate from the transmitting probe, and a plate wave is generated. A method in which a wave is propagated through the thin plate to pass through a contact surface, the passed plate wave is received by a receiving probe, and a contact stress is measured using the sound pressure of the received plate wave as an evaluation index.
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EP0387996A3 (en) * | 1989-03-14 | 1991-04-10 | ROLLS-ROYCE plc | A stress wave load cell |
EP0387995A3 (en) * | 1989-03-14 | 1991-04-10 | Rolls-Royce Dsv Limited | A stress wave load cell |
JP2006177933A (en) * | 2004-11-24 | 2006-07-06 | Jtekt Corp | Sensor device and rolling bearing having sensor |
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