JP6384263B2

JP6384263B2 - Echo characteristic correction method

Info

Publication number: JP6384263B2
Application number: JP2014213519A
Authority: JP
Inventors: 安彦臂
Original assignee: JTEKT Corp
Current assignee: JTEKT Corp
Priority date: 2014-10-20
Filing date: 2014-10-20
Publication date: 2018-09-05
Anticipated expiration: 2034-10-20
Also published as: JP2016080568A

Description

本発明は、互いに異なる材質で形成された第１部材と第２部材との接触面の周囲に形成された空間の一部に充填された液体の膜厚を、超音波を用いて計測する際に用いるエコー特性を補正する、エコー特性補正方法に関する。 In the present invention, when the thickness of a liquid filled in a part of a space formed around the contact surface between the first member and the second member formed of different materials is measured using ultrasonic waves. The present invention relates to an echo characteristic correction method for correcting an echo characteristic used in the above.

例えば、ガラスの略平板の第１部材に、ガラスの略球体の第２部材を接触させて、第１部材と第２部材の接点を含む接触面の周囲に形成された空間の少なくとも一部に潤滑油を充填した場合、その油膜の膜厚は、光干渉縞を利用した光干渉計測方法にて計測することができる。しかし、この光干渉計測方法では、第１部材と第２部材の少なくとも一方が透明でなければならないので、例えば非透明な金属の軌道輪（第１部材に相当）と、非透明な鋼球（第２部材に相当）と、にて構成された転がり軸受装置等には適用できない。 For example, the first member of the substantially flat glass plate is brought into contact with the second member of the substantially spherical glass member, and at least part of the space formed around the contact surface including the contact points of the first member and the second member. When lubricating oil is filled, the film thickness of the oil film can be measured by an optical interference measurement method using optical interference fringes. However, in this optical interference measurement method, since at least one of the first member and the second member must be transparent, for example, a non-transparent metal race (corresponding to the first member) and a non-transparent steel ball ( It corresponds to the second member) and cannot be applied to a rolling bearing device or the like constituted by

非透明な第１部材に、非透明な第２部材の曲面を接触させて、その接触面の周囲に形成された空間の少なくとも一部に充填した液体の膜厚を計測する方法としては、超音波を利用した超音波計測方法を利用することができる。超音波計測方法は、発信した超音波の反射波の強度（エコー強度）を検出することで、エコー強度に応じた膜厚を計測することができる。 As a method of measuring the film thickness of the liquid filled in at least a part of the space formed around the contact surface by bringing the curved surface of the non-transparent second member into contact with the non-transparent first member, An ultrasonic measurement method using sound waves can be used. The ultrasonic measurement method can measure the film thickness according to the echo intensity by detecting the intensity (echo intensity) of the reflected wave of the transmitted ultrasonic wave.

例えば特許文献１には、非透明なシリンダ（第１部材に相当）と、非透明なピストンリング（第２部材に相当）と、の間に形成された油膜の膜厚を、超音波探触子を用いて計測する際に使用される較正曲線データを精度よく簡単に得ることができる、膜厚測定のための膜厚較正曲線の取得方法が開示されている。特許文献１では、異なる膜厚についてそれぞれ、膜形成部からの反射波であるエコー高さ信号を超音波探触子により受信し、エコー高さ信号を標準化したエコー高さ比を演算し、予め設定された第１膜厚値と第２膜厚値の間におけるエコー高さ比の変化割合を演算し、この変化割合と膜厚値の関係を較正曲線として取得している。 For example, Patent Document 1 discloses an ultrasonic probe for the film thickness of an oil film formed between a non-transparent cylinder (corresponding to a first member) and a non-transparent piston ring (corresponding to a second member). A method of obtaining a film thickness calibration curve for film thickness measurement, which can easily and accurately obtain calibration curve data used when measuring using a child, is disclosed. In Patent Document 1, an echo height signal that is a reflected wave from a film forming unit is received by an ultrasonic probe for each of different film thicknesses, an echo height ratio obtained by standardizing the echo height signal is calculated, A change ratio of the echo height ratio between the set first film thickness value and the second film thickness value is calculated, and the relationship between the change ratio and the film thickness value is acquired as a calibration curve.

特開２００７−２１２４１０号公報JP 2007-212410 A

特許文献１に記載の発明では、シリンダ（第１部材）とピストンリング（第２部材）を想定しているので、シリンダとピストンリングとが接触している場合を想定していない。つまり、特許文献１には、シリンダとピストンリングが非接触であって、シリンダとピストンリングとの間の膜厚と、標準化したエコー高さ（エコー高さ比）と、の関係を示している。このため、膜厚がゼロから大きくなるに従って、標準化したエコー高さも徐々に増加している。従って、標準化したエコー高さ（エコー高さ比）を計測すれば、膜厚を１つに特定することができる。 In invention of patent document 1, since the cylinder (1st member) and the piston ring (2nd member) are assumed, the case where the cylinder and the piston ring are contacting is not assumed. In other words, Patent Document 1 shows a relationship between a cylinder and a piston ring that are not in contact with each other, and a film thickness between the cylinder and the piston ring and a standardized echo height (echo height ratio). . For this reason, as the film thickness increases from zero, the standardized echo height gradually increases. Therefore, if the standardized echo height (echo height ratio) is measured, the film thickness can be specified as one.

しかし、互いに異なる材質の第１部材と第２部材が接している場合では、特許文献１に記載されているような、膜厚が増加するに従ってエコー高さ比も増加するような、膜厚とエコー高さ比との関係が得られない場合がある。互いに異なる材質の第１部材と第２部材が接している場合、図５の例に示すように、第１部材２１と第２部材２２との接触面の中心である接触中心Ｓからの距離とエコー比との関係を示す距離・エコー比特性（図５中における『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）は、接触中心Ｓからの距離をゼロから徐々に大きくしていった場合、エコー比は、接触面の境界近傍までは徐々に減少し、接触面の境界近傍を越えた場合は徐々に増加する、という特性を有する。膜厚を求めるためには、この『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）と、第１部材２１と第２部材２２の形状等から理論的に求めた、接触中心Ｓからの距離と間隔（第１部材と第２部材との隙間）との関係を示す『距離・間隔特性』（図５参照）と、を予め作成しておく。なお、エコー比（Ｈ）とは、予め、第２部材と液体を取り除いた第１部材のみで測定したエコー強度に基づいたエコー強度を基準エコー強度（ｈｏ）として取得しておき、計測対象物で計測したエコー強度（ｈ）を、基準エコー強度（ｈｏ）で除算した値である（Ｈ＝ｈ／ｈｏ）。そして、実際の計測対象物で計測したエコー強度からエコー比を求め、求めたエコー比と『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）から、計測したエコー比に対応する距離を求め、求めた距離と『距離・間隔特性』から、間隔（すなわち膜厚）を求める。しかし、図５の例に示す『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）では、例えば計測したエコー強度から求めたエコー比がＨ１ＡＢであった場合、当該エコー比Ｈ１ＡＢと『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）から求められる距離は１つに特定されず、距離Ｄ１Ａと距離Ｄ１Ｂの２つが特定されてしまう。そしてこの距離Ｄ１Ａと距離Ｄ１Ｂと、『距離・間隔特性』からは、間隔（膜厚）Ｌ１Ａと間隔（膜厚）Ｌ１Ｂの２つが特定されてしまい、膜厚を１つに特定することができない。そして、この問題は、特許文献１に記載された発明を用いて較正しても解決することができない。 However, when the first member and the second member made of different materials are in contact with each other, as described in Patent Document 1, the film thickness is such that the echo height ratio increases as the film thickness increases. In some cases, the relationship with the echo height ratio cannot be obtained. When the first member and the second member made of different materials are in contact with each other, as shown in the example of FIG. 5, the distance from the contact center S that is the center of the contact surface between the first member 21 and the second member 22 The distance / echo ratio characteristic (“distance / echo ratio characteristic” in FIG. 5 (when the first member and the second member are made of different materials) indicating the relationship with the echo ratio gradually increases the distance from the contact center S from zero. The echo ratio has a characteristic that the echo ratio gradually decreases to near the boundary of the contact surface, and gradually increases when the contact surface boundary is exceeded. Is the distance from the contact center S theoretically determined from this “distance / echo ratio characteristic” (when the first member and the second member are made of different materials) and the shapes of the first member 21 and the second member 22. Shows the relationship between distance and distance (gap between the first member and the second member) Characteristics ”(see FIG. 5) are prepared in advance, and the echo ratio (H) is the echo intensity based on the echo intensity measured in advance only with the second member and the first member from which the liquid is removed. Is the value obtained by dividing the echo intensity (h) measured by the measurement object by the reference echo intensity (ho) (H = h / ho). The echo ratio is obtained from the echo intensity measured at the measurement object, and the distance corresponding to the measured echo ratio is calculated from the obtained echo ratio and the “distance / echo ratio characteristics” (when the first member and the second member are made of different materials). The distance (that is, the film thickness) is obtained from the obtained distance and the “distance / spacing characteristics.” However, the “distance / echo ratio characteristics” shown in the example of FIG. In the case of), for example, from the measured echo intensity When the calculated echo ratio is H1AB, the distance obtained from the echo ratio H1AB and “distance / echo ratio characteristics” (when the first member and the second member are made of different materials) is not specified as one. The distance D1A and the distance D1B are specified, and the distance D1A, the distance D1B, and the “distance / interval characteristics” specify the distance (film thickness) L1A and the distance (film thickness) L1B. The film thickness cannot be specified as one, and this problem cannot be solved even by calibrating using the invention described in Patent Document 1.

本発明は、このような点に鑑みて創案されたものであり、互いに異なる材質で形成された第１部材と第２部材とを接触させた接触面の周囲に形成された空間の少なくとも一部に充填された液体の膜厚を計測する際に利用する、第１部材と第２部材の接触面の中心である接触中心からの距離とエコー比との関係を示す距離・エコー比特性を、接触中心からの距離がゼロから大きくなるに従って、エコー比も徐々に大きくなるような特性へと補正する、エコー特性補正方法を提供することを課題とする。 The present invention was devised in view of such points, and at least a part of a space formed around the contact surface where the first member and the second member formed of different materials are brought into contact with each other. The distance / echo ratio characteristic indicating the relationship between the distance from the contact center, which is the center of the contact surface of the first member and the second member, and the echo ratio is used when measuring the film thickness of the liquid filled in It is an object of the present invention to provide an echo characteristic correction method in which the echo ratio is gradually increased as the distance from the contact center increases from zero.

上記課題を解決するため、本発明に係るエコー特性補正方法は次の手段をとる。まず、本発明の第１の発明は、互いに異なる材質で形成された第１部材と第２部材とを接触させた接触面の周囲に形成された空間の少なくとも一部に充填された液体の膜厚を超音波を用いて計測する際のエコー特性を補正するエコー特性補正方法である。そして、前記第１部材は、表面と裏面を有しており、前記第２部材の形状は、前記第１部材の裏面と対向する面が、前記第１部材に向かって少なくとも１つの曲率を有する凸形状を有しており、前記第１部材と前記第２部材は、前記第１部材を上側として前記第１部材の裏面に前記第２部材の表面が接触するように上下に配置され、前記第１部材と前記第２部材との接触面の周囲に形成された空間の少なくとも一部には液体が充填されており、超音波伝導媒体を介して前記第１部材の表面の側に配置されて前記第１部材の表面から裏面に向かう超音波を発信するとともに発信した超音波の反射波を検出する超音波プローブと、前記超音波プローブを制御する制御手段と、を用いる。そして、前記超音波プローブから超音波を発信し、発信された前記超音波が前記第１部材の裏面にて反射した第１部材裏面反射波と、発信された前記超音波が前記第２部材の表面にて反射した第２部材表面反射波と、が合成された合成反射波のエコー強度を、少なくとも前記接触面の中心である接触中心から所定距離までの間で検出する、合成反射波検出ステップと、予め求めた基準エコー強度であって前記第２部材と前記液体を排除して前記第１部材のみの状態にて前記第１部材の表面から裏面に向かう超音波を発信して前記第１部材の裏面にて反射した前記第１部材裏面反射波のエコー強度に基づいた前記基準エコー強度にて、前記合成反射波検出ステップにて検出したエコー強度を除算したエコー比を求める、エコー比算出ステップと、前記接触中心からの距離と、前記エコー比算出ステップにて求めた前記接触中心からの各距離のエコー比と、の関係を示す距離・エコー比特性であって前記接触中心からの距離が前記接触面の境界近傍までの間では徐々にエコー比が減少する傾向を有し、かつ前記接触中心からの距離が前記境界近傍を越えた場合は徐々にエコー比が増加する傾向を有する前記距離・エコー比特性を、前記接触面の大きさと、前記超音波プローブから発信される超音波の音圧強度分布特性と、に基づいて、前記接触中心から前記境界近傍までの前記エコー比を補正し、前記接触中心から離れるに従って徐々にエコー比が増加する傾向を有する距離・補正エコー比特性を作成する、距離・補正エコー比特性作成ステップと、を有する、エコー特性補正方法である。 In order to solve the above problems, the echo characteristic correction method according to the present invention takes the following means. A first aspect of the present invention is a liquid film filled in at least a part of a space formed around a contact surface where a first member and a second member made of different materials are brought into contact with each other. This is an echo characteristic correction method for correcting an echo characteristic when measuring thickness using ultrasonic waves. The first member has a front surface and a back surface, and the shape of the second member is such that the surface facing the back surface of the first member has at least one curvature toward the first member. The first member and the second member are arranged up and down so that the surface of the second member contacts the back surface of the first member with the first member as the upper side, At least a part of the space formed around the contact surface between the first member and the second member is filled with liquid, and is disposed on the surface side of the first member via an ultrasonic conduction medium. And an ultrasonic probe for transmitting an ultrasonic wave from the front surface to the back surface of the first member and detecting a reflected wave of the transmitted ultrasonic wave, and a control means for controlling the ultrasonic probe. Then, an ultrasonic wave is transmitted from the ultrasonic probe, and the transmitted ultrasonic wave is reflected on the back surface of the first member, and the transmitted ultrasonic wave is reflected on the second member. A combined reflected wave detection step for detecting an echo intensity of a combined reflected wave obtained by combining the second member surface reflected wave reflected by the surface at least from a contact center that is the center of the contact surface to a predetermined distance. The first echo by transmitting ultrasonic waves from the front surface to the back surface of the first member in a state where the second member and the liquid are excluded and only the first member is present, with the reference echo intensity determined in advance. Echo ratio calculation for obtaining an echo ratio obtained by dividing the echo intensity detected in the combined reflected wave detection step with the reference echo intensity based on the echo intensity of the first member back surface reflected wave reflected on the back surface of the member Step and A distance / echo ratio characteristic indicating a relationship between a distance from the contact center and an echo ratio of each distance from the contact center obtained in the echo ratio calculating step, wherein the distance from the contact center is the contact ratio. The distance / echo has a tendency that the echo ratio gradually decreases until near the boundary of the surface, and the echo ratio tends to increase gradually when the distance from the contact center exceeds the vicinity of the boundary. The ratio characteristic is corrected based on the size of the contact surface and the sound pressure intensity distribution characteristic of the ultrasonic wave transmitted from the ultrasonic probe, the echo ratio from the contact center to the vicinity of the boundary, A distance / corrected echo ratio characteristic creating step for creating a distance / corrected echo ratio characteristic having a tendency that the echo ratio gradually increases as the distance from the contact center increases. .

次に、本発明の第２の発明は、上記第１の発明に係るエコー特性補正方法であって、前記超音波プローブから発信される超音波は、焦点位置を調整可能であって、前記第１部材の裏面に焦点が調整されており、前記距離・補正エコー比特性作成ステップにおいて、前記接触中心から前記境界近傍までの前記エコー比を、前記第１部材と前記第２部材との前記接触面である略円を上面として前記第２部材の下面までに位置する仮想的な略円柱である仮想接触円柱と、予め求めた、前記超音波の前記焦点から下方に広がる音圧強度分布に基づいた仮想的な立体であって前記超音波の発信方向に沿って切断した断面の輪郭の形状が正規分布曲線状となる仮想音圧強度分布立体と、に基づいた補正量にて補正する、エコー特性補正方法である。 Next, a second invention of the present invention is the echo characteristic correcting method according to the first invention, wherein the ultrasonic wave transmitted from the ultrasonic probe is capable of adjusting a focal position, The focal point is adjusted to the back surface of one member, and the echo ratio from the contact center to the vicinity of the boundary is determined as the contact between the first member and the second member in the distance / corrected echo ratio characteristic creating step. Based on a virtual contact cylinder that is a virtual substantially circular cylinder located up to the lower surface of the second member with a substantially circular surface as the upper surface, and a sound pressure intensity distribution that is obtained in advance downward from the focal point of the ultrasonic wave. An echo that is corrected with a correction amount based on a virtual sound pressure intensity distribution solid that is a virtual solid that has a cross-sectional contour shape cut along the transmission direction of the ultrasonic waves and has a normal distribution curve shape. This is a characteristic correction method.

次に、本発明の第３の発明は、上記第２の発明に係るエコー特性補正方法であって、前記距離・補正エコー比特性作成ステップにおいて、前記接触中心から前記境界近傍までの前記接触中心から各距離の前記エコー比を、「前記各距離におけるエコー比」−「前記接触面における前記超音波の反射率」＊「前記各距離における前記仮想接触円柱と前記仮想音圧強度分布立体とが重なる部分の体積／前記仮想音圧強度分布立体の体積」にて求める、エコー特性補正方法である。 Next, a third invention of the present invention is the echo characteristic correction method according to the second invention, wherein, in the distance / corrected echo ratio characteristic creation step, the contact center from the contact center to the vicinity of the boundary. The echo ratio at each distance is expressed as “echo ratio at each distance” − “reflectance of the ultrasonic wave at the contact surface” * “the virtual contact cylinder and the virtual sound pressure intensity distribution solid at each distance”. This is an echo characteristic correction method obtained by “volume of overlapping portion / volume of virtual sound pressure intensity distribution solid”.

第１の発明によれば、接触中心からの距離がゼロから大きくなるに従って、接触面の境界近傍まではエコー比が徐々に減少し、接触面の境界近傍を越えた場合は徐々に増加する距離・エコー比特性を、接触中心からの距離がゼロから大きくなるに従って徐々にエコー比が増加する傾向を有する距離・補正エコー比特性へと補正するために、第１部材と第２部材とが接触している接触面の大きさと、超音波プローブから発信される超音波の音圧強度分布特性と、に基づいて適切に補正することができる。 According to the first invention, as the distance from the contact center increases from zero, the echo ratio gradually decreases to the vicinity of the boundary of the contact surface, and gradually increases when the vicinity of the boundary of the contact surface is exceeded. In order to correct the echo ratio characteristic to a distance / corrected echo ratio characteristic in which the echo ratio tends to gradually increase as the distance from the contact center increases from zero, the first member and the second member contact each other. It is possible to appropriately correct based on the size of the contact surface and the sound pressure intensity distribution characteristic of the ultrasonic wave transmitted from the ultrasonic probe.

第２の発明によれば、接触面の大きさに基づいた仮想接触円柱と、超音波の音圧強度分布に基づいた仮想音圧強度分布立体と、に基づいて補正することで、接触中心からの距離がゼロから大きくなるに従って、接触面の境界近傍まではエコー比が徐々に減少し、接触面の境界近傍を越えた場合は徐々に増加する距離・エコー比特性を、接触中心からの距離がゼロから大きくなるに従って徐々にエコー比が増加する傾向を有する距離・補正エコー比特性へと、適切に補正することができる。 According to the second invention, by correcting based on the virtual contact cylinder based on the size of the contact surface and the virtual sound pressure intensity distribution solid based on the ultrasonic sound pressure intensity distribution, As the distance increases from zero, the echo ratio gradually decreases to the vicinity of the boundary of the contact surface, and gradually increases when it exceeds the boundary of the contact surface. Thus, it is possible to appropriately correct the distance / corrected echo ratio characteristic in which the echo ratio tends to gradually increase as the value increases from zero.

第３の発明によれば、上記の距離・エコー比特性を、上記の距離・補正エコー比特性へと、より具体的に、より適切に補正することができる。 According to the third aspect of the invention, the distance / echo ratio characteristic can be more specifically and appropriately corrected to the distance / correction echo ratio characteristic.

外輪と、内輪と、複数の転動体と、を有する転がり軸受装置の外観の例を説明する図である。It is a figure explaining the example of the external appearance of the rolling bearing apparatus which has an outer ring | wheel, an inner ring | wheel, and a some rolling element. 図１におけるＩＩ−ＩＩ断面図である。It is II-II sectional drawing in FIG. 図２における外輪と転動体をモデル化した例を説明する図である。It is a figure explaining the example which modeled the outer ring | wheel and rolling element in FIG. 超音波計測装置の全体構成の例を説明する図である。It is a figure explaining the example of the whole structure of an ultrasonic measuring device. 接触中心からの距離とエコー比との関係を示す距離・エコー比特性（第１部材と第２部材が異なる材質の場合）の例と、接触中心からの距離と、第１部材と第２部材との間隔との関係を示す距離・間隔特性の例と、接触中心からの距離とエコー比との関係を示す距離・エコー比特性（第１部材と第２部材が同一の材質の場合）の例とを説明する図である。Example of distance / echo ratio characteristics (in the case where the first member and the second member are made of different materials) indicating the relationship between the distance from the contact center and the echo ratio, the distance from the contact center, the first member and the second member Examples of distance / echo characteristics indicating the relationship between the distance to the center and distance / echo ratio characteristics indicating the relationship between the distance from the contact center and the echo ratio (when the first member and the second member are made of the same material) It is a figure explaining an example. 発信された超音波の焦点の下方に広がる音圧強度分布と、当該音圧強度分布の計測方法を説明する図である。It is a figure explaining the sound pressure intensity distribution which spreads below the focus of the transmitted ultrasonic wave, and the measuring method of the said sound pressure intensity distribution. 計測された音圧強度分布の概略形状を説明する図である。It is a figure explaining the schematic shape of the measured sound pressure intensity distribution. 仮想接触円柱と仮想音圧強度分布立体との重畳状態を説明する平面図と側面図である。It is the top view and side view explaining the superposition state of a virtual contact cylinder and a virtual sound pressure intensity distribution solid. 接触中心からの距離とエコー比との関係を示す距離・エコー比特性の例（第１部材と第２部材が異なる材質の場合）と、接触中心からの距離と、仮想音圧強度分布立体の体積に対する仮想接触円柱と仮想音圧強度分布立体との重畳体積の体積比との関係を示す距離・重畳体積比特性の例と、距離・エコー比特性と距離・重畳体積比特性とに基づいて補正した距離・補正エコー比特性の例とを説明する図である。Examples of distance / echo ratio characteristics (in the case where the first member and the second member are made of different materials) showing the relationship between the distance from the contact center and the echo ratio, the distance from the contact center, and the virtual sound pressure intensity distribution solid Based on distance / superimposed volume ratio characteristics example showing the relationship between the volume ratio of superimposed volume of virtual contact cylinder and virtual sound pressure intensity distribution solid to volume, distance / echo ratio characteristics and distance / superimposed volume ratio characteristics It is a figure explaining the example of the correct | amended distance and correction | amendment echo ratio characteristic.

以下に本発明を実施するための形態を図面を用いて説明する。なお、Ｘ軸、Ｙ軸、Ｚ軸が記載されている図において、Ｘ軸とＹ軸とＺ軸は互いに直交しており、Ｚ軸は鉛直上方に向かう方向を示している。 EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. In the drawings in which the X axis, the Y axis, and the Z axis are described, the X axis, the Y axis, and the Z axis are orthogonal to each other, and the Z axis indicates a direction that extends vertically upward.

●［液体の膜厚の計測対象物の例（図１、図２）と計測対象物のモデル（図３）］
図１は、液体の膜厚の計測対象物の例である転がり軸受装置１００の外観を示しており、図２は、図１の転がり軸受装置１００のＩＩ−ＩＩ断面図を示している。転がり軸受装置１００は、外輪１２１と、内輪１２３と、複数の転動体１２２等にて構成されている。なお、図１及び図２の例では、隣り合う転動体１２２の間隔を保持する保持器の記載を省略している。 ● [Example of measurement target of liquid film thickness (Fig. 1, Fig. 2) and model of measurement target (Fig. 3)]
FIG. 1 shows an appearance of a rolling bearing device 100 as an example of a liquid film thickness measurement object, and FIG. 2 shows a II-II cross-sectional view of the rolling bearing device 100 of FIG. The rolling bearing device 100 includes an outer ring 121, an inner ring 123, a plurality of rolling elements 122, and the like. In addition, in the example of FIG.1 and FIG.2, description of the holder | retainer holding the space | interval of the adjacent rolling element 122 is abbreviate | omitted.

図１及び図２に示すように、外輪１２１は、内周面に凹状の外輪側軌道面１２１Ｋを有する円環状である。また内輪１２３は、外周面に凹状の内輪側軌道面１２３Ｋを有する円環状である。そして図２に示すように、外輪側軌道面１２１Ｋと転動体１２２との接触面の周囲に形成された空間の少なくとも一部には、潤滑油が充填された液体膜Ｍ（油膜）が形成されている。また、内輪側軌道面１２３Ｋと転動体１２２との接触面の周囲に形成された空間の少なくとも一部にも、潤滑油が充填された液体膜Ｍ（油膜）が形成されている。本実施の形態では、図２において、外輪１２１の表面１２１Ａの側から、外輪１２１の裏面１２１Ｂの側に向かって超音波を発信して、外輪１２１の裏面１２１Ｂと、転動体１２２の表面１２２Ａ（外輪に対向する面）との接点を含む接触面の周囲に形成された空間の少なくとも一部に充填された液体膜Ｍの膜厚を計測する際のエコー特性の補正方法について説明する。 As shown in FIGS. 1 and 2, the outer ring 121 has an annular shape having a concave outer ring side raceway surface 121K on the inner peripheral surface. The inner ring 123 has an annular shape having a concave inner ring side raceway surface 123K on the outer peripheral surface. As shown in FIG. 2, a liquid film M (oil film) filled with lubricating oil is formed in at least a part of the space formed around the contact surface between the outer ring raceway surface 121K and the rolling element 122. ing. A liquid film M (oil film) filled with lubricating oil is also formed in at least a part of the space formed around the contact surface between the inner ring raceway surface 123K and the rolling element 122. In the present embodiment, in FIG. 2, ultrasonic waves are transmitted from the surface 121A side of the outer ring 121 toward the back surface 121B side of the outer ring 121, and the back surface 121B of the outer ring 121 and the surface 122A ( A method of correcting the echo characteristics when measuring the film thickness of the liquid film M filled in at least a part of the space formed around the contact surface including the contact point with the surface facing the outer ring) will be described.

なお、転がり軸受装置１００における外輪の形状や転動体の形状に対して、計測に都合の良い形状としたモデルを図３に示し、以降、この図３のモデルの形状を用いて説明する。図３のモデルでは、外輪の代わりに、Ｚ軸方向の厚さ２１Ｔが一定の略平板の第１部材２１を用い、転動体の代わりに、第１部材２１に向かって少なくとも１つの曲率を有する凸形状を有する第２部材２２を用いている。図３に示す第２部材２２は、接触面の中心である接触中心Ｓを含む曲率であって外周部ＳＬと外周部ＳＲとの間の曲率と、外周部ＳＬよりも左側及び外周部ＳＲよりも右側の曲率と、の異なる曲率を有する部材である。そして第１部材２１と第２部材２２とが接触中心Ｓを含む接触面にて接触しており、接触中心Ｓを含む接触面の周囲に形成された空間の少なくとも一部に、液体膜Ｍが形成されている。また、符号２１Ａは第１部材２１の上面（表面）を示し、符号２１Ｂは第１部材２１の下面（裏面）を示し、符号２２Ａは第２部材２２の上面（表面であって第１部材に対向する面）を示し、符号２２Ｂは第２部材２２の下面（裏面）を示している。また接触中心Ｓは、第１部材２１と第２部材２２が面で接触している接触面の中心位置となる点を示している。 FIG. 3 shows a model that is convenient for measurement with respect to the shape of the outer ring and the shape of the rolling element in the rolling bearing device 100, and the following description will be made using the model shape of FIG. In the model of FIG. 3, a substantially flat first member 21 having a constant thickness 21T in the Z-axis direction is used instead of the outer ring, and at least one curvature is provided toward the first member 21 instead of the rolling element. A second member 22 having a convex shape is used. The second member 22 shown in FIG. 3 has a curvature including the contact center S that is the center of the contact surface, the curvature between the outer peripheral portion SL and the outer peripheral portion SR, the left side of the outer peripheral portion SL, and the outer peripheral portion SR. Is a member having a curvature different from the curvature on the right side. The first member 21 and the second member 22 are in contact with each other at the contact surface including the contact center S, and the liquid film M is formed in at least a part of the space formed around the contact surface including the contact center S. Is formed. Reference numeral 21A indicates the upper surface (front surface) of the first member 21, reference numeral 21B indicates the lower surface (back surface) of the first member 21, and reference numeral 22A indicates the upper surface (front surface of the first member 21). 22B indicates the lower surface (back surface) of the second member 22. The contact center S indicates a point that is the center position of the contact surface where the first member 21 and the second member 22 are in contact with each other.

●［超音波計測装置１の全体構成（図４）］
次に図４を用いて、超音波計測装置１の全体構成の例について説明する。超音波計測装置１は、超音波プローブ４０と、制御手段６０及び記憶手段と、支持部材８３、基台８１、８２、プローブホルダ７２、プローブアーム７１、媒体保持部材５１、シール部材５２、等を有している。なお、上下に重ねられた第１部材２１と第２部材２２の状態については、図３に示すとおりであるので説明を省略する。 ● [Overall configuration of ultrasonic measuring device 1 (FIG. 4)]
Next, an example of the overall configuration of the ultrasonic measurement apparatus 1 will be described with reference to FIG. The ultrasonic measurement apparatus 1 includes an ultrasonic probe 40, a control unit 60, a storage unit, a support member 83, bases 81 and 82, a probe holder 72, a probe arm 71, a medium holding member 51, a seal member 52, and the like. Have. In addition, about the state of the 1st member 21 and the 2nd member 22 which were piled up and down, since it is as showing in FIG. 3, description is abbreviate | omitted.

超音波プローブ４０は、プローブホルダ７２を介してプローブアーム７１にて支持されている。そして超音波プローブ４０は、制御手段６０からの制御信号に基づいて第１部材２１の上面（表面）から下面（裏面）に向かう超音波を発信する。そして超音波プローブ４０は、発信した超音波に対する反射波を検出し、検出信号を制御手段に出力する。なお、超音波の発信と反射波の受信を行う超音波プローブ４０の先端部は、超音波伝導媒体Ｂに浸かるように配置されている。なお、超音波プローブ４０は複数の超音波探触子を有しており、当該複数の超音波探触子がそれぞれのタイミングで発信した超音波は、ビーム状となって焦点Ｐを形成する。そして制御手段６０は、複数の超音波探触子のそれぞれから発信する超音波のタイミングを適切に調整することで、焦点Ｐの位置を調整可能である。そして焦点Ｐの位置は、第１部材２１の下面となるように調整されている。 The ultrasonic probe 40 is supported by a probe arm 71 via a probe holder 72. The ultrasonic probe 40 transmits ultrasonic waves from the upper surface (front surface) to the lower surface (back surface) of the first member 21 based on a control signal from the control means 60. And the ultrasonic probe 40 detects the reflected wave with respect to the transmitted ultrasonic wave, and outputs a detection signal to a control means. Note that the tip of the ultrasonic probe 40 that transmits ultrasonic waves and receives reflected waves is disposed so as to be immersed in the ultrasonic conductive medium B. Note that the ultrasonic probe 40 has a plurality of ultrasonic probes, and the ultrasonic waves transmitted by the plurality of ultrasonic probes at respective timings form a beam to form a focal point P. The control means 60 can adjust the position of the focal point P by appropriately adjusting the timing of the ultrasonic waves transmitted from each of the plurality of ultrasonic probes. The position of the focal point P is adjusted to be the lower surface of the first member 21.

制御手段６０は、例えばパーソナルコンピュータであって記憶手段を収容しており、超音波プローブ４０に制御信号を出力し、超音波プローブ４０から検出信号を取り込む。また制御手段６０は、プローブアーム７１に制御信号を出力して超音波プローブ４０の位置をＸ軸方向及びＹ軸方向に移動させることができる。そして記憶手段には、後述するように、基準エコー強度、距離・エコー比特性、距離・間隔特性、距離・重畳体積比特性、距離・補正エコー比特性、等が記憶されている。 The control means 60 is, for example, a personal computer and contains a storage means. The control means 60 outputs a control signal to the ultrasonic probe 40 and takes in a detection signal from the ultrasonic probe 40. The control unit 60 can output a control signal to the probe arm 71 to move the position of the ultrasonic probe 40 in the X-axis direction and the Y-axis direction. As will be described later, the storage means stores reference echo intensity, distance / echo ratio characteristics, distance / interval characteristics, distance / superimposed volume ratio characteristics, distance / corrected echo ratio characteristics, and the like.

支持部材８３は、上下に重ねられた第１部材２１と第２部材２２を把持し、所定の荷重で第１部材２１を第２部材２２に押し付けている。また、基台８１、８２は、支持部材８３を固定する台である。 The support member 83 holds the first member 21 and the second member 22 stacked one above the other and presses the first member 21 against the second member 22 with a predetermined load. The bases 81 and 82 are tables for fixing the support member 83.

プローブホルダ７２は、プローブアーム７１に取り付けられており、超音波プローブ４０を保持している。またプローブアーム７１は、制御手段６０からの制御信号に基づいて、プローブホルダ７２に保持された超音波プローブ４０をＸＹ平面内で移動させる。 The probe holder 72 is attached to the probe arm 71 and holds the ultrasonic probe 40. The probe arm 71 moves the ultrasonic probe 40 held by the probe holder 72 within the XY plane based on a control signal from the control means 60.

媒体保持部材５１は、媒体保持部材５１の内面と第１部材２１の上面（及び支持部材８３の上面）とで形成された凹状の空間内に、超音波を伝達することが可能な媒体である超音波伝導媒体Ｂ（例えば水）を保持する。またシール部材５２は、媒体保持部材５１と支持部材８３との間を密封する。 The medium holding member 51 is a medium capable of transmitting ultrasonic waves into a concave space formed by the inner surface of the medium holding member 51 and the upper surface of the first member 21 (and the upper surface of the support member 83). An ultrasonic conducting medium B (for example, water) is held. The seal member 52 seals between the medium holding member 51 and the support member 83.

●［超音波計測装置１を用いて、距離・エコー比特性を取得する手順（図５）］
次に、上記の超音波計測装置１を用いて、超音波プローブ４０を、第１部材２１と第２部材２２との接触面の接触中心Ｓの真上となる位置からＸ軸方向（図５中において右方向）に走査しながら超音波の発信し、発信した超音波に対する反射波のエコー強度を検出し、そのエコー強度に基づいた距離・エコー比特性の取得方法について説明する。なお、図５中において符号ＳＳは、第１部材２１と第２部材２２との接触面の境界となる位置を示す接触境界を示している。 ● [Procedure for obtaining distance / echo ratio characteristics using the ultrasonic measurement apparatus 1 (FIG. 5)]
Next, using the ultrasonic measurement apparatus 1 described above, the ultrasonic probe 40 is moved in the X-axis direction (FIG. 5) from the position directly above the contact center S of the contact surface between the first member 21 and the second member 22. A method of acquiring distance / echo ratio characteristics based on the transmission of ultrasonic waves while scanning in the right direction), detecting the echo intensity of reflected waves with respect to the transmitted ultrasonic waves, and the echo intensity will be described. In FIG. 5, reference sign SS indicates a contact boundary indicating a position that is a boundary of the contact surface between the first member 21 and the second member 22.

制御手段６０は、超音波プローブ４０から超音波を発信し、発信された超音波が第１部材２１の裏面（下面）にて反射した第１部材裏面反射波と、発信された超音波が第２部材２２の表面（上面）にて反射した第２部材表面反射波と、が合成された合成反射波のエコー強度（反射波の最大振幅）を、少なくとも接触中心ＳからＸ軸方向に所定距離となる位置までの間で検出する。このステップは、合成反射波検出ステップに相当する。 The control means 60 transmits an ultrasonic wave from the ultrasonic probe 40, and the transmitted ultrasonic wave is reflected on the back surface (lower surface) of the first member 21, and the transmitted ultrasonic wave is first. The echo intensity (maximum amplitude of the reflected wave) of the combined reflected wave obtained by combining the second member surface reflected wave reflected by the surface (upper surface) of the two members 22 is at least a predetermined distance from the contact center S in the X-axis direction. Detect until the position. This step corresponds to a composite reflected wave detection step.

次に制御手段６０は、予め求めた基準エコー強度であって（図５に示す第１部材２１と第２部材２２と液体膜Ｍを有する状態から）第２部材２２と液体（液体膜Ｍ）を排除して第１部材２１のみの状態にて第１部材２１の上面から下面に向かう超音波を発信して第１部材２１の下面にて反射した第１部材裏面反射波のエコー強度に基づいた基準エコー強度にて、合成反射波検出ステップにて検出した各距離に対応する各エコー強度を除算して、各距離に対応した各エコー比を求める。なお、基準エコー強度は、第１部材２１のみの場合において、例えば接触中心Ｓから前記所定距離となる位置までのエコー強度の平均値である。ここで、各距離に対応した各エコー比＝Ｈ、各距離にて計測した各エコー強度＝ｈ、基準エコー強度＝ｈｏとすると、以下の（式１）にて、各距離におけるエコー比Ｈを求める。このステップは、エコー比算出ステップに相当する。
Ｈ＝ｈ／ｈｏ（式１） Next, the control means 60 is the reference echo intensity obtained in advance (from the state having the first member 21, the second member 22, and the liquid film M shown in FIG. 5) and the second member 22 and the liquid (liquid film M). Based on the echo intensity of the first member back surface reflected wave transmitted from the upper surface of the first member 21 to the lower surface and reflected by the lower surface of the first member 21 with only the first member 21 removed Each echo intensity corresponding to each distance is obtained by dividing each echo intensity corresponding to each distance detected in the combined reflected wave detection step by the reference echo intensity. Note that the reference echo intensity is an average value of echo intensity from the contact center S to the position at the predetermined distance, for example, when only the first member 21 is used. Here, assuming that each echo ratio corresponding to each distance = H, each echo intensity measured at each distance = h, and reference echo intensity = ho, the echo ratio H at each distance is expressed by the following (Equation 1). Ask. This step corresponds to an echo ratio calculation step.
H = h / ho (Formula 1)

●［第１部材２１と第２部材２２とが同一の材質の場合］
第１部材２１と第２部材２２とが同一の材質の場合は、接触中心Ｓからの距離と、上記の手順にて求めたエコー比Ｈと、の関係を示す距離・エコー比特性は、図５中の『距離・エコー比特性』（第１部材と第２部材が同一の材質の場合）に示すとおりである。この特性では、接触中心Ｓからの距離がゼロから大きくなるに従って、エコー比が徐々に増加する傾向を有しているので、エコー比Ｈが特定されると、距離（接触中心Ｓからの距離）を１つに特定することができる。また、記憶手段には、予め、基準エコー強度と、第１部材２１と第２部材２２の形状（特に第２部材２２の各位置の曲率半径）とヘルツ接触理論と接触荷重等から理論的に求めた、接触中心Ｓからの距離と間隔（第１部材と第２部材との隙間）との関係を示す（図５に示す）『距離・間隔特性』が記憶されている。第１部材２１と第２部材２２とが同一の材質の場合、例えば求めたエコー比がＨ１Ａであった際は、制御手段６０は、エコー比Ｈ１Ａと、図５中の『距離・エコー比特性』（第１部材と第２部材が同一の材質の場合）とに基づいて距離Ｄ１Ａを特定する。そして特定した距離Ｄ１Ａと、図５中の『距離・間隔特性』とに基づいて間隔Ｌ１Ａを特定する。この特定した間隔Ｌ１Ａが、エコー比Ｈ１Ａを検出した位置（接触中心Ｓからの距離）における液体膜Ｍの膜厚である。 [When the first member 21 and the second member 22 are made of the same material]
When the first member 21 and the second member 22 are made of the same material, the distance / echo ratio characteristic indicating the relationship between the distance from the contact center S and the echo ratio H obtained by the above procedure is shown in FIG. 5, “Distance / Echo Ratio Characteristics” (when the first member and the second member are made of the same material). In this characteristic, since the echo ratio has a tendency to gradually increase as the distance from the contact center S increases from zero, when the echo ratio H is specified, the distance (distance from the contact center S) is determined. Can be specified as one. In addition, the storage means theoretically in advance from the reference echo intensity, the shape of the first member 21 and the second member 22 (particularly, the radius of curvature of each position of the second member 22), Hertz contact theory, contact load and the like. The obtained “distance / interval characteristics” indicating the relationship between the distance from the contact center S and the interval (gap between the first member and the second member) (shown in FIG. 5) is stored. When the first member 21 and the second member 22 are made of the same material, for example, when the obtained echo ratio is H1A, the control means 60 determines the echo ratio H1A and the “distance / echo ratio characteristics” in FIG. ] (When the first member and the second member are made of the same material), the distance D1A is specified. Then, the interval L1A is specified based on the specified distance D1A and the “distance / interval characteristics” in FIG. This specified interval L1A is the film thickness of the liquid film M at the position where the echo ratio H1A is detected (distance from the contact center S).

●［第１部材２１と第２部材２２とが異なる材質の場合］
第１部材２１と第２部材２２とが異なる材質の場合は、接触中心Ｓからの距離と、上記の手順にて求めたエコー比Ｈと、の関係を示す距離・エコー比特性は、図５中の『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）に示すとおりである。この特性では、接触中心Ｓからの距離がゼロから接触境界ＳＳの近傍まではエコー比は徐々に減少し、接触中心Ｓからの距離が接触境界ＳＳの近傍を越えた場合はエコー比は徐々に増加している。第１部材２１と第２部材２２とが異なる材質の場合、例えば求めたエコー比がＨ１ＡＢであった際は、制御手段６０は、エコー比Ｈ１ＡＢと、図５中の『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）とに基づいて距離Ｄ１Ａと距離Ｄ１Ｂのそれぞれを特定する。そして特定した距離Ｄ１Ａと距離Ｄ１Ｂと、図５中の『距離・間隔特性』とに基づいて間隔Ｌ１Ａと間隔Ｌ１Ｂのそれぞれを特定する。この特定した間隔Ｌ１Ａ、及び間隔Ｌ１Ｂが、エコー比Ｈ１ＡＢを検出した位置（接触中心Ｓからの距離）における液体膜Ｍの膜厚であるが、間隔Ｌ１Ａと間隔Ｌ１Ｂのどちらが正しい膜厚であるかわからない。そこで、以下の手順に従って、『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）を補正する。 [When the first member 21 and the second member 22 are made of different materials]
When the first member 21 and the second member 22 are made of different materials, the distance / echo ratio characteristic indicating the relationship between the distance from the contact center S and the echo ratio H obtained by the above procedure is shown in FIG. As shown in “Distance / Echo Ratio Characteristics” (when the first member and the second member are made of different materials). In this characteristic, the echo ratio gradually decreases from the distance from the contact center S to near the contact boundary SS, and the echo ratio gradually decreases when the distance from the contact center S exceeds the vicinity of the contact boundary SS. It has increased. When the first member 21 and the second member 22 are made of different materials, for example, when the obtained echo ratio is H1AB, the control means 60 determines the echo ratio H1AB and “distance / echo ratio characteristics” in FIG. Based on (when the first member and the second member are made of different materials), the distance D1A and the distance D1B are specified. Then, the distance L1A and the distance L1B are specified based on the specified distance D1A and distance D1B and the “distance / interval characteristics” in FIG. The specified interval L1A and interval L1B are the film thicknesses of the liquid film M at the position where the echo ratio H1AB is detected (distance from the contact center S). Which of the intervals L1A and L1B is the correct film thickness? do not know. Therefore, according to the following procedure, the “distance / echo ratio characteristic” (when the first member and the second member are made of different materials) is corrected.

●［超音波の焦点Ｐから下方に広がる音圧強度分布（図６、図７）、及び接触面と音圧強度分布との関係（図８）］
図６は、超音波プローブ４０から発信された超音波の焦点Ｐが第１部材２１の下面２１Ｂに設定されている際の、焦点Ｐから下方に広がる音圧強度分布の計測方法の例を示している。第１部材２１の下側は、第２部材２２と同じ音響インピーダンスに調整された油等の超音波伝導媒体ＢＡが充填されている。そして当該超音波伝導媒体ＢＡ内にはハイドロフォン等の音圧強度検出手段ＨＰが配置されている。制御手段６０は、焦点Ｐの位置に対する種々の位置（超音波伝導媒体ＢＡ内の種々の位置）に音圧強度検出手段ＨＰを移動させて、各位置での音圧強度を検出し、音圧強度の分布状態を計測する。計測された音圧強度の分布状態を形状で示すと、図７の例に示す形状となる。この図７に示す音圧強度の分布状態の形状を、超音波の発信方向に沿って切断（Ｚ軸を含む面にて切断）した場合、断面の輪郭の形状は、正規分布曲線に類似している。理想的な焦点Ｐは「点」であるが、実際には焦点Ｐは「点」ではなく、所定の径を有する「面」である。 ● [Sound pressure intensity distribution spreading downward from the focal point P of the ultrasonic waves (FIGS. 6 and 7) and the relationship between the contact surface and the sound pressure intensity distribution (FIG. 8)]
FIG. 6 shows an example of a method for measuring the sound pressure intensity distribution extending downward from the focal point P when the focal point P of the ultrasonic wave transmitted from the ultrasonic probe 40 is set on the lower surface 21 </ b> B of the first member 21. ing. The lower side of the first member 21 is filled with an ultrasonic conductive medium BA such as oil adjusted to the same acoustic impedance as the second member 22. A sound pressure intensity detecting means HP such as a hydrophone is disposed in the ultrasonic conduction medium BA. The control means 60 moves the sound pressure intensity detecting means HP to various positions (various positions in the ultrasonic conduction medium BA) with respect to the position of the focal point P, detects the sound pressure intensity at each position, and detects the sound pressure. Measure the intensity distribution. When the distribution state of the measured sound pressure intensity is shown by shape, the shape shown in the example of FIG. 7 is obtained. When the shape of the sound pressure intensity distribution state shown in FIG. 7 is cut along the ultrasonic wave transmission direction (cut along the plane including the Z axis), the shape of the cross-sectional contour is similar to a normal distribution curve. ing. The ideal focal point P is a “point”, but actually the focal point P is not a “point” but a “plane” having a predetermined diameter.

図８は、第１部材２１と第２部材２２との接触面と、超音波の焦点Ｐに基づいた音圧強度分布との平面視と側面視による仮想イメージ図を示している。ここで、符号ＶＳは、第１部材２１と第２部材２２との接触面である略円を上面として第２部材２２の下面までに位置する仮想的な略円柱である仮想接触円柱を示している。従って、仮想接触円柱ＶＳは、接触中心ＳをとおるＺ軸方向の直線ＺＶＳを軸とした略円柱状であり、上面は接触境界ＳＳを輪郭とする略円であり、直線ＺＶＳから側面までの距離は接触中心Ｓから接触境界ＳＳまでの距離と等しい。また符合ＶＢは、図７に示したように、超音波の焦点Ｐから下方に広がる音圧強度分布に基づいた仮想的な立体であって超音波の発信方向に沿って切断した場合の断面の輪郭が正規分布状となる仮想音圧強度分布立体を示している。 FIG. 8 shows a virtual image diagram in plan view and side view of the contact surface between the first member 21 and the second member 22 and the sound pressure intensity distribution based on the focal point P of the ultrasonic wave. Here, the symbol VS indicates a virtual contact cylinder that is a virtual substantially cylinder positioned up to a lower surface of the second member 22 with a substantially circle that is a contact surface between the first member 21 and the second member 22 as an upper surface. Yes. Therefore, the virtual contact cylinder VS has a substantially cylindrical shape with the Z axis direction straight line ZVS passing through the contact center S as an axis, and the upper surface is a substantially circle having the contact boundary SS as an outline, and the distance from the straight line ZVS to the side surface. Is equal to the distance from the contact center S to the contact boundary SS. In addition, as shown in FIG. 7, the symbol VB is a virtual solid based on the sound pressure intensity distribution that spreads downward from the focal point P of the ultrasonic wave, and has a cross section when cut along the ultrasonic wave transmission direction. A virtual sound pressure intensity distribution solid whose contour has a normal distribution shape is shown.

図８の例では、接触中心Ｓから焦点Ｐまでの距離である焦点位置距離ＤＳＰが、仮想接触円柱ＶＳの半径ＲＶＳと仮想音圧強度分布立体ＶＢの上面の略円の半径ＲＶＢとの和よりも小さい場合（焦点位置距離ＤＳＰ＜半径ＲＶＳ＋半径ＲＶＢ）を示しており、仮想接触円柱ＶＳと仮想音圧強度分布立体ＶＢとが、ハッチングを施した位置で重畳している様子を示している。そして、当該ハッチングを施した部分の立体を重畳部ＶＤとする。ここで、仮想音圧強度分布立体ＶＢの体積（Ｖｂ）に対する重畳部ＶＤの体積（Ｖｄ）を重畳体積比（Ｒｒ）とすると、以下の（式２）が成立する。そして、下記の（式２）を、横軸を接触中心Ｓからの距離、縦軸を重畳体積比、としたグラフに示すと、図８に示す『距離・体積比特性』となる。
重畳体積比（Ｒｒ）＝重畳部ＶＤの体積（Ｖｄ）／仮想音圧強度分布立体ＶＢの体積（Ｖｂ）（式２） In the example of FIG. 8, the focal position distance DSP, which is the distance from the contact center S to the focal point P, is the sum of the radius RVS of the virtual contact cylinder VS and the radius RVB of the approximate circle on the upper surface of the virtual sound pressure intensity distribution solid VB. Is also small (focal position distance DSP <radius RVS + radius RVB), and the virtual contact cylinder VS and the virtual sound pressure intensity distribution solid VB are superimposed at the hatched positions. Then, the solid portion of the hatched portion is set as the overlapping portion VD. Here, when the volume (Vd) of the overlapping portion VD with respect to the volume (Vb) of the virtual sound pressure intensity distribution solid VB is the overlapping volume ratio (Rr), the following (Expression 2) is established. Then, when the following (formula 2) is shown in a graph in which the horizontal axis is the distance from the contact center S and the vertical axis is the superimposed volume ratio, the “distance / volume ratio characteristic” shown in FIG. 8 is obtained.
Superposed volume ratio (Rr) = Volume of superposed part VD (Vd) / Volume of virtual sound pressure intensity distribution solid VB (Vb) (Formula 2)

発明者は、重畳部ＶＤが、図５中の『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）において、接触中心Ｓからの距離がゼロから接触境界ＳＳの近傍まではエコー比が徐々に減少する原因である、と考え、以下の（式３）に示す補正量（Ａｄｊ）を考案した。なお、下記の補正量（Ａｄｊ）において、Ｚ１は第１部材２１の音響インピーダンスであり、Ｚ２は第２部材２２の音響インピーダンスである。なお、（式３）における（Ｚ１−Ｚ２）／（Ｚ１＋Ｚ２）を、接触面における超音波の反射率（Ｒｅｆ）とすると、（式３）は（式４）となる。
補正量（Ａｄｊ）＝［（Ｚ１−Ｚ２）／（Ｚ１＋Ｚ２）］＊重畳体積比（Ｒｒ）（式３）
補正量（Ａｄｊ）＝反射率（Ｒｅｆ）＊重畳体積比（Ｒｒ）（式４） The inventor believes that the overlapping portion VD has a distance from the contact center S from zero to the vicinity of the contact boundary SS in the “distance / echo ratio characteristics” in FIG. 5 (when the first member and the second member are different materials). Up to this point, it was considered that the echo ratio gradually decreased, and the correction amount (Adj) shown in the following (Equation 3) was devised. In the following correction amount (Adj), Z1 is the acoustic impedance of the first member 21, and Z2 is the acoustic impedance of the second member 22. If (Z1−Z2) / (Z1 + Z2) in (Expression 3) is the reflectance (Ref) of the ultrasonic wave on the contact surface, (Expression 3) becomes (Expression 4).
Correction amount (Adj) = [(Z1-Z2) / (Z1 + Z2)] * overlapping volume ratio (Rr) (Formula 3)
Correction amount (Adj) = Reflectance (Ref) * Overlapping volume ratio (Rr) (Formula 4)

●［距離・補正エコー比特性の作成（図９）］
そして、下記の（式５）に示すように、上記の（式１）のエコー比（Ｈ）から、上記の（式４）の補正量を減算することで、補正エコー比（ＨＨ）を作成し、作成した補正エコー比（ＨＨ）に基づいて、接触中心Ｓからの距離がゼロの位置から徐々に離れるに従って徐々に増加する傾向を有する、『距離・補正エコー比特性』（図９参照）を作成する。このステップは、距離・補正エコー比特性作成ステップに相当する。
補正エコー比（ＨＨ）
＝エコー比（Ｈ）−補正量（Ａｄｊ）
＝エコー比（Ｈ）−反射率（Ｒｅｆ）＊重畳体積比（Ｒｒ）
＝［計測したエコー強度（ｈ）／基準エコー強度（ｈｏ）］−［（Ｚ１−Ｚ２）／（Ｚ１＋Ｚ２）］＊［重畳部ＶＤの体積（Ｖｄ）／仮想音圧強度分布立体ＶＢの体積（Ｖｂ）］（式５） ● [Create distance / corrected echo ratio characteristics (Fig. 9)]
Then, as shown in (Equation 5) below, the corrected echo ratio (HH) is created by subtracting the correction amount in (Equation 4) from the echo ratio (H) in (Equation 1) above. Then, based on the created corrected echo ratio (HH), the “distance / corrected echo ratio characteristic” has a tendency to gradually increase as the distance from the contact center S gradually moves away from the zero position (see FIG. 9). Create This step corresponds to a distance / corrected echo ratio characteristic creation step.
Corrected echo ratio (HH)
= Echo ratio (H) -correction amount (Adj)
= Echo ratio (H) -Reflectance (Ref) * Overlapping volume ratio (Rr)
= [Measured echo intensity (h) / reference echo intensity (ho)]-[(Z1-Z2) / (Z1 + Z2)] * [volume of superimposition portion VD (Vd) / volume of virtual sound pressure intensity distribution volume VB ( Vb)] (Formula 5)

つまり、図９において、『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）のグラフから、仮想接触円柱と仮想音圧強度分布立体の『距離・重畳体積比特性』のグラフを減算すると、『距離・補正エコー比特性』（第１部材と第２部材が異なる材質の場合）のグラフを得ることができる。得られた『距離・補正エコー比特性』（第１部材と第２部材が異なる材質の場合）は、接触中心Ｓからの距離がゼロから大きくなるに従って、徐々に（補正）エコー比が増加する傾向を有している。従って、例えば、計測対象物の任意の位置の補正エコー比がＨＨ１であった場合、補正エコー比ＨＨ１と、『距離・補正エコー比特性』（第１部材と第２部材が異なる材質の場合）（図９参照）に基づいて、接触中心Ｓからの距離は距離Ｄ１Ｂの１つに特定される。そして、特定された距離Ｄ１Ｂと、図５に示す『距離・間隔特性』に基づいて、間隔Ｌ１Ｂ（膜厚Ｌ１Ｂ）が特定される。すなわち、計測した任意の位置に対応する膜厚は、膜厚Ｌ１Ｂである、と１つに特定することができる。 That is, in FIG. 9, from the graph of “distance / echo ratio characteristics” (when the first member and the second member are made of different materials), “distance / superimposed volume ratio characteristics” of the virtual contact cylinder and the virtual sound pressure intensity distribution solid. By subtracting this graph, a graph of “distance / corrected echo ratio characteristics” (when the first member and the second member are made of different materials) can be obtained. In the obtained “distance / corrected echo ratio characteristics” (when the first member and the second member are made of different materials), the (corrected) echo ratio gradually increases as the distance from the contact center S increases from zero. Has a tendency. Therefore, for example, when the corrected echo ratio at an arbitrary position of the measurement object is HH1, the corrected echo ratio HH1 and the “distance / corrected echo ratio characteristic” (when the first member and the second member are made of different materials). Based on (see FIG. 9), the distance from the contact center S is specified as one of the distances D1B. Then, based on the identified distance D1B and the “distance / interval characteristics” shown in FIG. 5, the interval L1B (film thickness L1B) is identified. That is, it can be specified that the film thickness corresponding to the measured arbitrary position is the film thickness L1B.

以上に説明したように、互いに異なる材質で形成された第１部材と第２部材とを接触させた接触面の周囲に形成された空間の少なくとも一部に充填された液体の膜厚を計測する際に利用する、第１部材と第２部材の接触面の中心である接触中心からの距離とエコー比との関係を示す『距離・エコー比特性』（第１部材と第２部材が異なる材質の場合）を、接触中心からの距離がゼロから大きくなるに従って、エコー比も徐々に大きくなるような特性［『距離・補正エコー比特性』（第１部材と第２部材が異なる材質の場合）］へと補正する。これにより、補正エコー比から特定される距離を１つにすることが可能であり、特定した１つの距離から、１つの膜厚を特定することができる。 As described above, the film thickness of the liquid filled in at least a part of the space formed around the contact surface where the first member and the second member made of different materials are brought into contact with each other is measured. "Distance / Echo Ratio Characteristic" indicating the relationship between the distance from the contact center, which is the center of the contact surface between the first member and the second member, and the echo ratio (materials different between the first member and the second member) )), The echo ratio gradually increases as the distance from the center of contact increases from zero ["Distance / corrected echo ratio characteristics" (when the first and second members are of different materials) ] To correct. Thereby, the distance specified from the corrected echo ratio can be made one, and one film thickness can be specified from the specified distance.

本発明のエコー特性補正方法の処理手順は、本発明の要旨を変更しない範囲で種々の変更、追加、削除が可能である。 The processing procedure of the echo characteristic correction method of the present invention can be variously changed, added, and deleted without changing the gist of the present invention.

また本実施の形態の説明では、第１部材と第２部材の材質が異なる材質である場合について説明した。例えば、第１部材の材質がガラス、第２部材の材質が鋼鉄の場合を含むが、第１部材と第２部材が互いに異なる材質であればよく、第１部材の材質と第２部材の材質は、ガラスや鋼鉄に限定されるものではない。 In the description of the present embodiment, the case where the materials of the first member and the second member are different materials has been described. For example, the material of the first member includes glass and the material of the second member is steel, but the first member and the second member may be different from each other. Is not limited to glass or steel.

また、本実施の形態にて説明した液体の膜厚は、潤滑油の膜厚に限定されず、水等の種々の液体の膜厚の計測に適用することが可能である。 The film thickness of the liquid described in the present embodiment is not limited to the film thickness of the lubricating oil, and can be applied to the measurement of the film thickness of various liquids such as water.

また、本実施の形態にて説明したエコー特性補正方法は、例えば、転動体（球、ころ等）と、内輪及び外輪と、が異なる材質の軸受装置（例えば、転動体が鋼鉄で、内輪及び外輪がセラミック等）の実機の動的条件下（軸受として作動状態）における液体膜厚（油膜厚さ）の計測にも適用可能である。また、セラミック板（第１部材）と鋼球（第２部材）の油膜厚さ計測用のモデル等にも適用可能である。 In addition, the echo characteristic correction method described in the present embodiment is, for example, a bearing device (for example, the rolling element is steel, the inner ring and the outer ring are made of a material different from the rolling element (ball, roller, etc.) It can also be applied to the measurement of liquid film thickness (oil film thickness) under dynamic conditions (acting as a bearing) of an actual machine with an outer ring of ceramic or the like. Moreover, it is applicable also to the model etc. for the oil film thickness measurement of a ceramic board (1st member) and a steel ball (2nd member).

また、本実施の形態にて説明したエコー特性補正方法は、動的条件下において液体膜厚の計測が可能であるので、潤滑油の供給量や、軌道の形状の効果や、異常診断（油膜切れの判定）等にも適用可能である。 In addition, since the echo characteristic correction method described in this embodiment can measure the liquid film thickness under dynamic conditions, the supply amount of lubricating oil, the effect of the shape of the track, and abnormality diagnosis (oil film) It can also be applied to (determination of cutting).

１超音波計測装置
２１第１部材
２１Ａ表面（上面）
２１Ｂ裏面（下面）
２２第２部材
２２Ａ表面（上面）
２２Ｂ裏面（下面）
４０超音波プローブ
５１媒体保持部材
５２シール部材
７１プローブアーム
７２プローブホルダ
６０制御手段
８１、８２基台
８３支持部材
Ｂ、ＢＡ超音波伝導媒体
ＨＰ音圧強度検出手段
Ｍ液体膜
Ｐ焦点
Ｓ接触中心
ＳＳ接触境界
ＶＢ仮想音圧強度分布立体
ＶＤ重畳部
ＶＳ仮想接触円柱

DESCRIPTION OF SYMBOLS 1 Ultrasonic measuring device 21 1st member 21A Surface (upper surface)
21B Back (bottom)
22 Second member 22A Surface (upper surface)
22B Back side (lower side)
40 Ultrasonic probe 51 Medium holding member 52 Seal member 71 Probe arm 72 Probe holder 60 Control means 81, 82 Base 83 Support member B, BA Ultrasonic conduction medium HP Sound pressure intensity detection means M Liquid film P Focus S Contact center SS Contact boundary VB Virtual sound pressure intensity distribution solid VD superposition part VS Virtual contact cylinder

Claims

互いに異なる材質で形成された第１部材と第２部材とを接触させた接触面の周囲に形成された空間の少なくとも一部に充填された液体の膜厚を超音波を用いて計測する際のエコー特性を補正するエコー特性補正方法であって、
前記第１部材は、表面と裏面を有しており、
前記第２部材の形状は、前記第１部材の裏面と対向する面が、前記第１部材に向かって少なくとも１つの曲率を有する凸形状を有しており、
前記第１部材と前記第２部材は、前記第１部材を上側として前記第１部材の裏面に前記第２部材の表面が接触するように上下に配置され、前記第１部材と前記第２部材との接触面の周囲に形成された空間の少なくとも一部には液体が充填されており、
超音波伝導媒体を介して前記第１部材の表面の側に配置されて前記第１部材の表面から裏面に向かう超音波を発信するとともに発信した超音波の反射波を検出する超音波プローブと、前記超音波プローブを制御する制御手段と、を用いて、
前記超音波プローブから超音波を発信し、発信された前記超音波が前記第１部材の裏面にて反射した第１部材裏面反射波と、発信された前記超音波が前記第２部材の表面にて反射した第２部材表面反射波と、が合成された合成反射波のエコー強度を、少なくとも前記接触面の中心である接触中心から所定距離までの間で検出する、合成反射波検出ステップと、
予め求めた基準エコー強度であって前記第２部材と前記液体を排除して前記第１部材のみの状態にて前記第１部材の表面から裏面に向かう超音波を発信して前記第１部材の裏面にて反射した前記第１部材裏面反射波のエコー強度に基づいた前記基準エコー強度にて、前記合成反射波検出ステップにて検出したエコー強度を除算したエコー比を求める、エコー比算出ステップと、
前記接触中心からの距離と、前記エコー比算出ステップにて求めた前記接触中心からの各距離のエコー比と、の関係を示す距離・エコー比特性であって前記接触中心からの距離が前記接触面の境界近傍までの間では徐々にエコー比が減少する傾向を有し、かつ前記接触中心からの距離が前記境界近傍を越えた場合は徐々にエコー比が増加する傾向を有する前記距離・エコー比特性を、前記接触面の大きさと、前記超音波プローブから発信される超音波の音圧強度分布特性と、に基づいて、前記接触中心から前記境界近傍までの前記エコー比を補正し、前記接触中心から離れるに従って徐々にエコー比が増加する傾向を有する距離・補正エコー比特性を作成する、距離・補正エコー比特性作成ステップと、を有する、
エコー特性補正方法。 When measuring the film thickness of the liquid filled in at least a part of the space formed around the contact surface where the first member and the second member made of different materials are in contact with each other using ultrasonic waves An echo characteristic correction method for correcting an echo characteristic,
The first member has a front surface and a back surface;
The shape of the second member has a convex shape in which the surface facing the back surface of the first member has at least one curvature toward the first member,
The first member and the second member are arranged vertically so that the surface of the second member is in contact with the back surface of the first member with the first member as the upper side, and the first member and the second member At least part of the space formed around the contact surface with the liquid is filled with liquid,
An ultrasonic probe that is disposed on the surface side of the first member via an ultrasonic conduction medium and transmits an ultrasonic wave directed from the front surface to the back surface of the first member and detects a reflected wave of the transmitted ultrasonic wave; Using a control means for controlling the ultrasonic probe,
The ultrasonic wave is transmitted from the ultrasonic probe and the transmitted ultrasonic wave is reflected on the back surface of the first member, and the transmitted ultrasonic wave is transmitted to the surface of the second member. A combined reflected wave detecting step for detecting an echo intensity of the combined reflected wave synthesized with the second member surface reflected wave reflected at least from a contact center that is the center of the contact surface to a predetermined distance;
A reference echo intensity determined in advance, the second member and the liquid are excluded, and an ultrasonic wave directed from the front surface to the back surface of the first member is transmitted only in the state of the first member. An echo ratio calculating step for obtaining an echo ratio obtained by dividing the echo intensity detected in the combined reflected wave detection step with the reference echo intensity based on the echo intensity of the first member back surface reflected wave reflected on the back surface; ,
A distance / echo ratio characteristic indicating a relationship between a distance from the contact center and an echo ratio of each distance from the contact center obtained in the echo ratio calculating step, wherein the distance from the contact center is the contact ratio. The distance / echo has a tendency that the echo ratio gradually decreases until near the boundary of the surface, and the echo ratio tends to increase gradually when the distance from the contact center exceeds the vicinity of the boundary. The ratio characteristic is corrected based on the size of the contact surface and the sound pressure intensity distribution characteristic of the ultrasonic wave transmitted from the ultrasonic probe, the echo ratio from the contact center to the vicinity of the boundary, A distance / corrected echo ratio characteristic creating step for creating a distance / corrected echo ratio characteristic in which the echo ratio tends to gradually increase as the distance from the contact center increases.
Echo characteristic correction method.

請求項１に記載のエコー特性補正方法であって、
前記超音波プローブから発信される超音波は、焦点位置を調整可能であって、前記第１部材の裏面に焦点が調整されており、
前記距離・補正エコー比特性作成ステップにおいて、
前記接触中心から前記境界近傍までの前記エコー比を、
前記第１部材と前記第２部材との前記接触面である略円を上面として前記第２部材の下面までに位置する仮想的な略円柱である仮想接触円柱と、
予め求めた、前記超音波の前記焦点から下方に広がる音圧強度分布に基づいた仮想的な立体であって前記超音波の発信方向に沿って切断した断面の輪郭の形状が正規分布曲線状となる仮想音圧強度分布立体と、に基づいた補正量にて補正する、
エコー特性補正方法。 The echo characteristic correction method according to claim 1,
The ultrasonic wave transmitted from the ultrasonic probe can adjust the focal position, and the focal point is adjusted on the back surface of the first member,
In the distance / corrected echo ratio characteristic creating step,
The echo ratio from the contact center to the vicinity of the boundary,
A virtual contact cylinder that is a virtual substantially circular cylinder positioned up to the lower surface of the second member with the upper surface of the substantially circle that is the contact surface of the first member and the second member;
It is a virtual solid based on the sound pressure intensity distribution that spreads downward from the focal point of the ultrasonic wave that has been obtained in advance, and the shape of the profile of the cross section cut along the transmission direction of the ultrasonic wave is a normal distribution curve shape A correction amount based on the virtual sound pressure intensity distribution solid
Echo characteristic correction method.

請求項２に記載のエコー特性補正方法であって、
前記距離・補正エコー比特性作成ステップにおいて、
前記接触中心から前記境界近傍までの前記接触中心から各距離の前記エコー比を、
「前記各距離におけるエコー比」−「前記接触面における前記超音波の反射率」＊「前記各距離における前記仮想接触円柱と前記仮想音圧強度分布立体とが重なる部分の体積／前記仮想音圧強度分布立体の体積」にて求める、
エコー特性補正方法。

The echo characteristic correction method according to claim 2,
In the distance / corrected echo ratio characteristic creating step,
The echo ratio of each distance from the contact center from the contact center to the vicinity of the boundary,
“Echo ratio at each distance” − “Reflectivity of the ultrasonic wave at the contact surface” * “Volume of the portion where the virtual contact cylinder and the virtual sound pressure intensity distribution solid at each distance overlap / the virtual sound pressure” `` Volume of intensity distribution solid ''
Echo characteristic correction method.