JP6879030B2 - Measuring device and measuring method - Google Patents

Description

The present invention relates to a measuring device and a measuring method for determining the thickness of lubricating oil.

For example, when two metal members roll and make contact with each other, lubricating oil is used. As a result, an oil film is formed between the contact surfaces of the two members, and damage such as seizure can be prevented. Since a favorable lubricating state can be obtained by setting the thickness of the oil film between the two members and the thickness of the lubricating oil around it to a predetermined value, efforts are being made to measure the thickness of the lubricating oil in the research on lubricating oil. It has been damaged.

As a measurement method thereof, for example, as described in Patent Document 1, an oil in which a fluorescent substance is dispersed is applied between two members, and the brightness of fluorescence emitted from the fluorescent substance is measured by irradiating the two members with laser light. There is a method (laser-induced fluorescence method). This is a measurement method utilizing the fact that the amount of the fluorescent substance increases as the thickness of the lubricating oil increases, so that the brightness increases in proportion to the thickness of the lubricating oil. As a mechanical element in which the two members come into contact with each other via the lubricating oil as described above, for example, there are rolling bearings and gears.

Japanese Unexamined Patent Publication No. 06-174431

In the case of the above-mentioned measuring method, the correlation between the thickness of the lubricating oil and the brightness is obtained in advance using a test gauge. For example, as shown in FIG. 7A, a lubricating oil 93 containing a fluorescent substance is sandwiched between a flat surface 91 and a transparent flat plate 92, and the end portion of the flat plate 92 is placed on a block gauge 94 having a specified thickness. Therefore, the value Dn of the gap at each position Pn in the horizontal direction between the plane 91 and the flat plate 92 can be obtained by calculation. Then, a laser beam is irradiated and the brightness at each position Pn in the horizontal direction is measured by a camera (not shown) on the flat plate 92 (see FIG. 7B). Thereby, the correlation between the thickness of the lubricating oil and the brightness can be obtained.

Then, for example, a rolling bearing is coated with a lubricating oil containing a fluorescent substance, irradiated with a laser beam, and an image showing the distribution of brightness between the rolling element (first member) and the raceway ring (second member) is acquired. .. From the brightness in the acquired image information, it is possible to obtain the thickness of the lubricating oil between these rolling elements and the raceway ring based on the correlation.

However, the state in which the correlation is acquired using the flat plate 92 (test gauge) and the state in which the images of the rolling element and the raceway ring are acquired in the rolling bearing which is the actual machine are different depending on the conditions such as time and place. Even if the thickness of the lubricating oil in the rolling bearing is obtained in this way, the accuracy may be lowered. The cause is, for example, that the intensity of the laser beam changes with time, or the fluorescent substance deteriorates with time. In addition, the fluorescence intensity may change due to changes in the surface state such as adhesion of lubricating oil components and changes in surface roughness.

Therefore, the present invention prevents the accuracy of the required lubricating oil thickness from being lowered even if the intensity of the irradiated light is changed, the fluorescent substance is deteriorated, or the state of the surface is changed. It is an object of the present invention to provide a measuring device and a measuring method that enable the above.

The present invention is a measuring device for determining the thickness of the lubricating oil in the first member and the second member whose geometric shapes are known to come into contact with each other through the lubricating oil containing a fluorescent substance, and the first member and the second member. An irradiation device that irradiates light toward a region including a region between two members, a photographing device that photographs a target region including the region between the two members, and a brightness of the target region from an image captured by the photographing device. The computing device includes an arithmetic device that acquires image information including the distribution of the above and obtains the thickness of the lubricating oil in the target region based on the image information, and the arithmetic device is based on the acquired image information from the geometric shape. The correlation between the distance between the two members at each position and the brightness at each position is obtained, and the brightness at each position in the target region obtained from the acquired image information is converted by the correlation and at each position. Find the thickness of the lubricating oil.

According to this measuring device, since the geometric shapes of the first member and the second member are known, the distance between these two members (that is, the thickness of the lubricating oil existing in the gap between the two members) and the brightness Correlation can be obtained from the image information acquired for obtaining the thickness of the lubricating oil at each position in the target region. Therefore, for example, even if the intensity of the irradiated light changes, the fluorescent substance deteriorates, or the state of the surface changes over time, it is possible to prevent the accuracy of the required lubricating oil thickness from decreasing. be able to.
The "thickness of the lubricating oil in the first member and the second member" is, in addition to the thickness of the lubricating oil between the two members, the thickness of the lubricating oil around the two members, for example, two. It is the thickness of the lubricating oil adhering to the surface of the first member and the thickness of the lubricating oil adhering to the surface of the second member in the vicinity of the inter-member region.

Further, the imaging device is configured to photograph the target region including the region between the two members between the first member and the second member that move relative to each other in contact with each other via the lubricating oil. Can be done. In this way, even when the first member and the second member move relative to each other, the brightness of each position in the target region can be converted by the correlation to obtain the thickness of the lubricating oil at each position. ..

Here, when the imaging device photographs the first member and the second member that move relative to each other over time and the arithmetic unit acquires a plurality of image information that is continuous over time, the lubricating oil at each position in the target region is used. The correlation may be obtained from another image information acquired immediately before (or immediately after) the image information acquired in order to obtain the thickness of the image. This is because it is unlikely that the light intensity will change or the fluorescent substance will deteriorate between a plurality of image information that are continuous over time (because the time interval between these acquisitions is short). Even if the correlation obtained from another image information immediately before (or immediately after) is used as described above, it is possible to prevent the accuracy of obtaining the thickness of the lubricating oil from being lowered.

However, the photographing device photographs the target area over time, and the computing device acquires a plurality of the image information from the captured images of the photographing device, and one of the plurality of the image information is the image information. It is preferable to obtain the thickness of the lubricating oil at each position by converting the brightness of each position in the target region obtained from the above by the correlation obtained from the geometric shape based on the one image information. .. In this way, the correlation is obtained from one of the acquired plurality of image information, and the brightness of each position in the target region obtained from the one image information is converted by this correlation. It is preferable to determine the thickness of the lubricating oil at each position. As a result, it is possible to more reliably prevent the accuracy of the required lubricating oil thickness from being lowered.

In addition, the target region including the region between the two members between the first member and the second member, which move relative to each other in contact with each other via the lubricating oil, is photographed over time, and the arithmetic unit may be used. A plurality of the image information is acquired from the captured images taken by the photographing device at different timings, and the correlation is obtained from each of the acquired plurality of the image information at each timing when the captured image is captured, and the correlation is obtained. In terms of conversion, it is preferable to obtain the thickness of the lubricating oil at each position in the target region at each timing when the captured image is taken. According to this configuration, the correlation is obtained for each of the image information acquired by being photographed at the first timing and the image information acquired by being photographed at another second timing, and the target is described. Since the thickness of the lubricating oil at each position in the region can be obtained, for example, it is possible to obtain information indicating a change over time with respect to the thickness of the lubricating oil at each position.

Further, it is preferable that the arithmetic unit obtains the correlation and also obtains an estimated correlation between a value larger than the maximum value of the distance between the two members and the brightness in the case of the value based on the tendency of the correlation. Since the distance between the two members at each position is the same as the thickness of the lubricating oil at each position, the correlation can be obtained up to the maximum value of the distance between the two members. When the lubricating oil at a specific position in the region has a thickness exceeding this maximum value, the thickness of the lubricating oil at this specific position cannot be obtained by the correlation (only), but the estimated correlation is obtained. As a result, it is possible to obtain the thickness of the lubricating oil having a thickness exceeding the maximum value of the distance between the two members.

In addition, the brightness of the lubricating oil containing a fluorescent substance may change due to a temperature change. In such a case, the photographing device photographs the target area over time, and the arithmetic unit acquires a plurality of the image information from the captured images of the photographing device and is based on each of the plurality of the image information. The correlation may be obtained and the change in the correlation may be determined. According to this configuration, for example, by determining the change in the correlation at the distance between the two members at the same position included in the two-member region, it is possible to obtain the temperature change of the lubricating oil in the two-member region. Become.

Further, the present invention is a measuring method for determining the thickness of the lubricating oil in the first member and the second member whose geometric shapes are known to come into contact with each other through the lubricating oil containing a fluorescent substance, and the first member and the first member. A step of irradiating light toward a region including a region between two members between the two members, a step of photographing a target region including the region between the two members, and a step of photographing the target region from an image obtained by the photographing. In the step of acquiring the image information including the distribution of the brightness and obtaining the thickness of the lubricating oil in the target region based on the image information, and in the step of obtaining the thickness of the lubricating oil, the acquired image information is included. Based on the geometric shape, the correlation between the distance between the two members at each position and the brightness at each position is obtained, and the brightness at each position in the target region obtained from the acquired image information is converted by the correlation. Then, the thickness of the lubricating oil at each position is obtained.

This measuring method is executed by the measuring device, and can exert the same effect as that of the measuring device. That is, for example, even if the intensity of the irradiated light changes or the fluorescent substance deteriorates over time, it is possible to prevent the accuracy of the required lubricating oil thickness from decreasing.

According to the present invention, it is possible to prevent the accuracy of the required lubricating oil thickness from being lowered even if the intensity of the irradiated light changes or the fluorescent substance deteriorates over time.

It is a block diagram which shows an example of the measuring apparatus of this invention. It is explanatory drawing of the outer ring and the ball in plane orthogonal coordinates. It is explanatory drawing which shows the function of the position which the distance from a Y axis is Xn, and the distance | distance of two members in the region between two members. It is a flow chart of the measurement method. It is a graph which shows the relationship between the position where the distance from the Y axis is Xn, and the brightness obtained by the image information in the region between two members. It is a graph which shows the correlation between the distance between two members, and the brightness. It is a figure explaining the conventional measurement method.

[Outline of measuring device and mechanical elements to be measured]
FIG. 1 is a block diagram showing an example of the measuring device of the present invention. The measuring device 10 is a device for determining the thickness of the lubricating oil in the mechanical element including the first member and the second member that come into contact with each other via the lubricating oil. In the present embodiment described below, the mechanical element is a rolling bearing (ball bearing) 20, the first member is an outer ring (first raceway ring) 21, and the second member is a ball (rolling element). 22. A plurality of balls 22 are interposed between the outer ring 21 and the inner ring (second raceway ring) 23, and the ball 22 is provided on the inner peripheral side of the outer ring 21 by the rotation of the inner ring 23. The inner ring orbits 25 provided on the outer peripheral side of the 24 and the inner ring 23 each roll and come into contact with each other. The outer ring 21 is held in a stationary state, and the ball 22 rolls and contacts the outer ring 21 due to the rotation of the inner ring 23 to move. This moving direction (rotational direction) is indicated by an arrow S. Each ball 22 is held at equal intervals by a cage (not shown). The rolling bearing 20 may be a roller bearing other than a ball bearing, or may be a roller bearing in which the rolling element is a roller. Further, the mechanical element for which the thickness of the lubricating oil 26 is measured may be other than the rolling bearing.

In this measuring device 10, the ball 22 and the inner ring 23 are made of steel (for example, bearing steel), but the outer ring 21 is made of a transparent material (glass or resin) that transmits light (for measurement). The ball 22 is a sphere, and as shown in FIG. 1, in a cross section that passes through the center C of the ball 22 and is orthogonal to the center line (not shown) of the rolling bearing 20, the cross-sectional shape of the ball 22 is a circle with a radius R. is there. The outer ring 21 and the inner ring 23 are annular, and the outer ring track 24 and the inner ring track 25 are annular surfaces having a predetermined radius larger than the radius R, but here, they are flat surfaces for ease of explanation. As described above, the geometric shapes of the balls 22 and the geometric shapes of the outer ring 21 and the inner ring 23 are known. The geometric shapes of the outer ring 21 and the ball 22 will be described later. The dimensional accuracy of each component such as the ball 22 and the outer ring 21 that make up the rolling bearing 20 is extremely high.

The rolling bearing 20 is lubricated by the lubricating oil 26, and the measuring device 10 determines the thickness of the lubricating oil 26 in the space N formed between the outer ring 21 and the inner ring 23. In the form shown in FIG. 1, a case where the thickness of the lubricating oil 26 adhering to the outer ring 21 is mainly obtained will be described. Oil or grease can be used as the lubricating oil 26. A fluorescent substance 27 is added to the lubricating oil 26, and the fluorescent substance 27 is dispersed and present in the lubricating oil 26, and emits fluorescence having a specific wavelength by light having a predetermined wavelength. The fluorescent substance 27 can be a fluorescent dye or fluorescent particles, and rhodamine B, coumarin, or the like can be used.

[About the configuration of the measuring device 10]
The measuring device 10 includes an irradiation device 11, a photographing device 12, and an arithmetic device 13. The measuring device 10 of the present embodiment further includes an optical filter 14.

The irradiation device 11 is installed on the outer side in the radial direction of the outer ring 21, and irradiates light having a predetermined wavelength toward a region Q including a region between two members 30 between the outer ring 21 and the ball 22. The irradiation device 11 of the present embodiment irradiates a laser beam (YAG laser) having a predetermined wavelength. That is, in the present embodiment, the thickness of the lubricating oil 26 is determined by using the laser-induced fluorescence method. Alternatively, the irradiation device 11 may be composed of LEDs. The lubricating oil 26 containing the fluorescent substance 27 receives the irradiation light from the irradiation device 11 and emits light. The emission wavelength of the lubricating oil 26 (fluorescent substance 27) is longer than the wavelength of the irradiation light.

The optical filter 14 is installed between the lens 15 of the photographing apparatus 12 and the rolling bearing 20 (outer ring 21). The optical filter 14 transmits light having an emission wavelength of the lubricating oil 26 (fluorescent substance 27), but does not transmit (blocks) the reflected light of the irradiation light. As a result, the photographing device 12 can photograph the luminescent image of the lubricating oil 26 (fluorescent substance 27) excluding the influence of the reflected light of the outer ring 21 and the ball 22.

The photographing device 12 of the present embodiment is composed of a CCD camera. The photographing device 12 is installed on the outer side in the radial direction of the outer ring 21, and acquires an image of the light emitting lubricating oil 26 through the transparent outer ring 21. A two-dimensional image of the target region 31 including the region between two members 30 can be acquired by the image sensor included in the photographing device 12. The target area 31 including the two-member area 30 photographed by the photographing device 12 may coincide with the area Q in which the irradiation device 11 illuminates the light, and the target area 31 may be narrower than the area Q. Good. The photographing device 12 outputs a signal corresponding to the brightness of the light received by each of a large number of light receiving elements of the image sensor as a photographed image. The arithmetic unit 13 acquires the output signal (photographed image), and the arithmetic unit 13 executes various processes based on the output signal.

The arithmetic unit 13 is composed of a computer, a storage unit 16 for storing various information (data), an arithmetic processing unit 17 composed of a CPU, and an output unit 18 for outputting various information (for example, an image of information). It is equipped with a display that outputs as. The arithmetic unit 13 acquires image information including the brightness distribution of the target region 31 from the captured image of the photographing device 12, and executes a process of obtaining the thickness of the lubricating oil 26 in the target region 31 based on the image information. .. The specific processing performed by the arithmetic unit 13 will be described later.

[Geometry of outer ring 21 and ball 22]
In FIG. 1, shape information obtained from known geometric shapes of the outer ring 21 and the ball 22 will be described. In the cross section of the rolling bearing 20 (a part thereof) shown in FIG. 1, plane orthogonal coordinates with the center C of the ball 22 as the origin are set. The plane (the cross section) of the Cartesian coordinates is a plane that passes through the center C of the ball 22 and is orthogonal to the center line of the rolling bearing 20. In the plane orthogonal coordinates, the radial direction of the ball 22 passing through the contact point P0 between the outer ring 21 and the ball 22 is the Y-axis direction, and the direction orthogonal to the Y-axis direction is the X-axis direction. FIG. 2 is an explanatory view of the outer ring 21 and the ball 22 in the plane orthogonal coordinates. The origin of the plane orthogonal coordinates may be another point.

With the ball 22 as a reference, the region on the moving direction (arrow S) side of the ball 22 (the region on the right side in FIG. 2) has more lubricating oil 26 than the region on the opposite side (the region on the left side in FIG. 2). It exists (thickly). Here, the region 30 between the two members between the outer ring 21 and the ball 22 in the region on the moving direction (arrow S) side of the ball 22 will be described. Lubricating oil 26 is present in the two-member region 30 (although not as a whole). In the intermember region 30 where the lubricating oil 26 exists, the distance (distance in the Y-axis direction) Dn between the outer ring 21 and the ball 22 at the position Pn separated from the Y-axis by a distance Xn is the lubricating oil at that position Pn. It is equal to the thickness tun of 26. The distance Dn in the Y-axis direction is also referred to as a geometric gap in the region 30 between the two members.

Since the geometric shapes of the outer ring 21 and the ball 22 are known, the distance Dn at the position Pn separated from the Y axis by a distance Xn is represented by the following equation (1).
Dn = R- (R ^2- Xn ² ) ^1/2 ... (1)

In the formula (1), since R is the radius of the ball 22 and is a known value, the interval Dn in the region between two members 30 is a function of the distance Xn from the Y axis. FIG. 3 is an explanatory diagram showing this function. As described above, this function (Equation (1), FIG. 3) is obtained by the outer ring 21 and the ball 22 whose geometric shapes are known. The interval Dn is equal to the thickness nt of the lubricating oil 26 in the intermember region 30 (Dn = tun). This function (Equation (1), FIG. 3) is stored in the storage unit 16 of the arithmetic unit 13 (see FIG. 1) as shape information of the region between two members 30. Based on this shape information and the captured image acquired from the photographing device 12, the arithmetic unit 13 determines the thickness of the lubricating oil 26 at each position in the target area 31 (see FIG. 1) as described below. Ask.

[Measurement method]
A method for determining the thickness of the lubricating oil 26 performed by the measuring device 10 configured as described above will be described. The rolling bearing 20 to be measured is in a state in which the inner ring 23 is rotated at a constant speed (see FIG. 1). FIG. 4 is a flow chart of the measurement method.

In FIG. 4, this measurement method includes an irradiation step S1, an imaging step S2, and a calculation step S3. In FIGS. 1 and 4, in the irradiation step S1, the irradiation device 11 irradiates light toward the region Q including the two-member region 30 between the outer ring 21 and the ball 22. In the photographing step S2, the photographing device 12 photographs the target area 31 including the area between the two members 30. In the calculation step S3, image information including the brightness distribution of the target region 31 is acquired from the image obtained by the photographing, and the thickness tm of the lubricating oil 26 at each position Pm of the target region 31 is calculated based on this image information. Ask. A specific example of each step will be described below.

In the irradiation step S1, the irradiation device 11 in the fixed state (see FIG. 1) emits light having a predetermined wavelength toward a region Q including the region between the two members 30 as described above for a part of the rotating rolling bearing 20. Irradiate. Since the rolling bearing 20 (inner ring 23) is rotating, in the photographing step S2, between the two members between the outer ring 21 and the ball 22 which move relative to each other in contact with each other via the lubricating oil 26 by the photographing device 12. The target area 31 including the area 30 is continuously photographed over time. Then, in the calculation step S3, the calculation device 13 acquires the image information according to one of the following measurement conditions, the first measurement condition and the second measurement condition.

<First measurement condition> ... "Acquire image information for each orbital period of the ball 22."
<Second measurement condition> ... "Acquire the image information of the time interval (cycle) of the value obtained by dividing the orbital period of the ball 22 by the number of balls 22."

In the case of the first measurement condition, the target region 31 including the intermember region 30 between the specific one ball 22 and the outer ring 21 among the plurality of balls 22 (because the photographing device 12 is fixed). Multiple image information of is acquired.
In the case of the second measurement condition, a plurality of image information of the target region 31 including the region between the two members 30 between each of the plurality of balls 22 and the outer ring 21 (because the photographing device 12 is fixed) is acquired. ..
Either the first measurement condition or the second measurement condition may be selected, and the arithmetic unit 13 acquires image information according to this selection. Regardless of which measurement condition is selected, the process of obtaining the correlation (first process) and the process of obtaining the thickness of the lubricating oil 26 (second process), which will be described later, are the same from the income image information.

When the arithmetic unit 13 acquires one image information from a plurality of captured images captured by the imaging device 12 at predetermined timings according to one of the first measurement condition and the second measurement condition. , The first process and the second process are executed. In the first process, based on the acquired image information, the distance (Pn in FIG. 2) between the two members 21 and 22 is determined from the geometric shape of the outer ring 21 and the ball 22 (that is, the shape information). This is a process for obtaining the correlation between Dn) and the brightness at each position (Pn). In the second process, the brightness of each position (Pm) in the target region 31 obtained from the acquired image information is converted by the correlation, and the thickness (tm) of the lubricating oil 26 at each position (Pm) is converted. Is the process of finding. In the following, the arithmetic unit 13 performs processing that does not particularly explain the subject.

The first treatment will be specifically described. The acquired image information includes the distribution of the brightness in the region 30 between the two members. Therefore, in the region 30 between the two members as shown in FIG. 5, the relationship (graph) between the position Pn at which the distance from the Y axis is Xn and the brightness (value) Ln obtained from the image information can be obtained. .. This relationship is stored in the storage unit 16 as luminance information. Based on the shape information shown in FIG. 3 and the luminance information shown in FIG. 5 stored in the storage unit 16, the interval Dn at each position Pn between the two members 21 and 22 and the luminance Ln at each position Pn Correlation K0 (solid line portion in FIG. 6) is obtained. Since the interval Dn is equal to the thickness nt of the lubricating oil 26 in the region 30 between the two members (Dn = tun), this correlation K0 is the thickness tun of the lubricating oil 26 and the brightness Ln in the case of the thickness nt. It becomes a correlation with. The correlation K0 between the thickness tn (interval Dn) and the brightness Ln is stored in the storage unit 16 in association with the image information for which the correlation K0 is to be obtained.

The second process will be specifically described. The acquired image information also includes a luminance distribution in a region other than the two-member region 30 in the target region 31 (see FIG. 1). Therefore, it is possible to acquire the information of the brightness (value) at the position Pm (see FIG. 2) of the region other than the region between the two members 30. Therefore, the arithmetic unit 13 obtains the thickness tm of the lubricating oil 26 corresponding to the brightness (value) at this position Pm from the correlation K0 (see FIG. 6). That is, the brightness (value) at the position Pm is converted by the correlation K0 to obtain the thickness tm of the lubricating oil 26 at this position Pm. For example, according to the image information, when the brightness (value) at a certain position included in the target area 31 is L1, the thickness of the lubricating oil 26 at this position is t1 according to the correlation K0 shown in FIG. It becomes. As described above, it is possible to obtain the thickness tm of the lubricating oil 26 at each position Pm in the target region 31.

When the arithmetic unit 13 obtains the thickness tm of the lubricating oil 26 at each position Pm in the target region 31, the position Pm and the thickness tm are associated with each other and stored in the storage unit 16. When the arithmetic unit 13 acquires a plurality of correspondence information corresponding to the position Pm and the thickness tm, for example, the distribution of the thickness tm of the lubricating oil 26 in the target region 31 is output to the output unit 18 (display) as an image. can do.

As described above, the measuring method performed by the measuring device 10 of the present embodiment determines the thickness tm of the lubricating oil 26 in the outer ring 21 and the ball 22 whose geometric shapes are known to come into contact with each other via the lubricating oil 26 containing the fluorescent substance 27. This is the method to obtain. According to this method, since the geometric shapes of the outer ring 21 and the ball 22 are known, the distance Dn between the two members 21 and 22 (that is, the thickness of the lubricating oil 26 existing in the gap between the two members 21 and 22). The correlation K0 between the tn) and the brightness Ln can be obtained from the image information acquired to obtain the thickness tm of the lubricating oil 26 at each position Pm in the target region 31. That is, in the present embodiment, the correlation K0 is obtained every time the image information is acquired, and the processing for obtaining the thickness tm of the lubricating oil 26 from the image information is performed based on the correlation K0. Therefore, for example, when the intensity of the light irradiated by the irradiation device 11 changes with time, the fluorescent substance 27 in the lubricating oil 26 deteriorates, or the correlation K0 changes with time due to disturbance. Even if there is, it is possible to prevent the accuracy of the required thickness tm of the lubricating oil 26 from being lowered. Further, even when the fluorescence intensity changes due to a change in surface condition such as adhesion of a lubricating oil component or a change in surface roughness, according to the present embodiment, the required accuracy of the thickness tm of the lubricating oil 26 is obtained. Can be prevented from decreasing.

As described above, since the interval Dn at each position Pn of the two members 21 and 22 is the same as the thickness tun of the lubricating oil 26 at each position Pn, theoretically, the interval Dn of the two members 21 and 22 The correlation K0 can be obtained up to the maximum value (radius R in this embodiment). However, as shown in FIG. 2, when the lubricating oil 26 does not exist in the entire region between the two members 21 and 22, or the lubricating oil at a specific position in the region other than the region between the two members 30, the maximum value ( When the thickness exceeds R), the thickness of the lubricating oil 26 at this specific position cannot be determined only by the correlation K0. Therefore, in the present embodiment, the arithmetic unit 13 additionally obtains the estimated correlation K1 (two-dot chain line portion in FIG. 6) described below. Thereby, for example, it is possible to obtain the thickness of the lubricating oil 26 having a thickness exceeding the maximum value (R) of the interval Dn between the two members 21 and 22.
That is, the correlation K0 obtained from the geometric shapes of the two members 21 and 22 shown by the solid line in FIG. 6 can be approximated to a predetermined function, and the arithmetic unit 13 can approximate this approximate function (hereinafter referred to as an approximate function). Call.) Is asked. Further, the arithmetic unit 13 uses the approximation function as the relationship (correlation) between the interval Dn and the luminance Ln for the range indicated by the alternate long and short dash line in FIG. It is obtained based on this, and this is referred to as the estimated correlation K1. For example, in the case of FIG. 6, since the correlation K0 is linear, its extension is defined as the estimated correlation K1. In this way, the arithmetic unit 13 obtains the correlation K0 and sets the estimated correlation K1 between the value larger than the maximum value of the interval Dn of the two members 21 and 22 and the brightness Ln in the case of the value of the correlation K1. Performs the desired process based on the tendency. Thereby, for example, the arithmetic unit 13 can obtain the thickness of the lubricating oil 26 having a thickness exceeding the maximum value (R) of the interval Dn between the two members 21 and 22.

Then, in the present embodiment, the photographing device 12 continuously photographs the target area 31 over time, and the arithmetic unit 13 measures the target area 31 regardless of whether it is the first measurement condition or the second measurement condition. , A plurality of continuous image information over time is acquired from the captured image of the photographing device 12. Then, the brightness of each position Pm in the target region 31 obtained from one of the acquired plurality of image information is obtained from the geometric shapes of the two members 21 and 22 based on this one image information. The thickness tm of the lubricating oil 26 at each position Pm is obtained by converting with the correlation K0. In this way, the correlation K0 is obtained from one of the acquired plurality of image information, and the brightness of each position Pm in the target region 31 obtained from this one image information is determined by the correlation K0. To obtain the thickness tm of the lubricating oil 26 at each position Pm. As a result, it is possible to prevent the measurement accuracy from being lowered more reliably.

The correlation K0 may be obtained from another image information acquired immediately before (or immediately after) the image information acquired in order to obtain the thickness tm of the lubricating oil 26 at each position Pm in the target region 31. This is because the time interval at which these images are acquired is short (for example, the time interval is several milliseconds) among a plurality of image information that are continuous over time, so that the light intensity changes or the fluorescent substance changes. This is because it is unlikely that the image will deteriorate, and it is possible to prevent the measurement accuracy from deteriorating even if the correlation K0 obtained from another image information immediately before (or immediately after) is used as described above. ..

Further, in the present embodiment, regardless of the first measurement condition or the second measurement condition, the arithmetic unit 13 acquires a plurality of image information from the captured images captured by the photographing device 12 at different timings. It will be. Then, the correlation K0 is obtained from each of the acquired plurality of image information, and the thickness tm of the lubricating oil 26 at each position Pm in the target region 31 is obtained by converting with the correlation K0. According to this configuration, for example, the correlation K0 is obtained for each of the image information acquired by being photographed at the first timing and the image information acquired by being photographed at another second timing. Since the thickness tm of the lubricating oil 26 at each position Pm in the target region 31 can be obtained, for example, it is possible to obtain information indicating a change over time with respect to the thickness tm of the lubricating oil 26 at each position Pm. It becomes.

Here, the measuring device 10 has a function of obtaining a temperature change of the lubricating oil 26 in addition to the function of obtaining the thickness of the lubricating oil 26 as described above. This is possible when the brightness of the lubricating oil 26 containing the fluorescent substance 27 changes due to a temperature change. In order to realize this function, the photographing device 12 photographs the target area 31 over time. Then, the arithmetic unit 13 acquires a plurality of continuous image information over time from the captured image of the photographing device 12. The arithmetic unit 13 obtains the correlation K0 based on each of the acquired plurality of image information. The above processing is the same as the case where the thickness of the lubricating oil 26 is obtained. In order to obtain the temperature change of the lubricating oil 26, the arithmetic unit 13 determines the change in the obtained correlation K0. The determination of the change in the correlation K0 is performed based on whether or not the brightness is changed at a predetermined position in the region 30 between the two members where the lubricating oil 26 is present. That is, the fact that the brightness changes with time at the predetermined position means that the temperature of the lubricating oil 26 at the predetermined position changes. Therefore, according to the arithmetic unit 13, it is possible to obtain the temperature change of the lubricating oil 26 in the region between the two members 30.

Each of the above-mentioned processes performed by the arithmetic unit 13 may be executed in a time zone that overlaps with the time zone in which the photographing device 12 performs shooting, but after the time zone in which the shooting image is recorded, for example, the photographed image is recorded. You may execute it with.

The embodiments disclosed as described above are exemplary in all respects and are not restrictive. That is, the measuring device and the measuring method of the present invention are not limited to the illustrated form, and may be other forms within the scope of the present invention.
In the above-described embodiment, the irradiation device 11 and the photographing device 12 are each set as one unit, but one or both of them may be used as a plurality of units, and a plurality of areas may be used for photographing and measuring. For example, when there are a plurality of photographing devices 12, one photographing device 12 mainly photographs the first member (outer ring 21), and the other photographing device 12 mainly photographs the second member (ball 22). May be good. The light irradiation direction by the irradiation device 11 and the photographing direction of the photographing device 12 may be not only the radial direction of the rolling bearing 20 but also the direction parallel to the axial direction of the rolling bearing 20.

In the above embodiment, the case where the first member and the second member whose geometric shapes are known to come into contact with each other via the lubricating oil 26 containing the fluorescent substance 27 are the outer ring 21 and the ball 22 has been described, but other than that. It may also be used as a ball 22 (rolling body) and a cage (not shown) that holds the ball 22.
Further, although the object of measurement is the rolling bearing 20, it may be a pair of gears that are in contact with each other. In the case of gears, since the tooth shape (involute curve) is known, a lubricating oil containing a fluorescent substance may be applied to these gears.

10: Measuring device 11: Irradiation device 12: Imaging device 13: Arithmetic device 21: Outer ring (first member) 22: Ball (second member)
26: Lubricating oil 27: Fluorescent substance 30: Area between two members 31: Target area K0: Correlation K1: Estimated correlation nt, tm: Lubricating oil thickness Pn, Pm: Position

Claims (7)

A measuring device for determining the thickness of the lubricating oil in the first member and the second member whose geometric shapes are known to come into contact with each other through the lubricating oil containing a fluorescent substance.
An irradiation device that irradiates light toward a region including a region between two members between the first member and the second member, and an irradiation device.
An imaging device that photographs the target area including the area between the two members, and
It is provided with an arithmetic unit that acquires image information including the brightness distribution of the target region from the captured image of the imaging device and obtains the thickness of the lubricating oil in the target region based on the image information.
The arithmetic device obtains the correlation between the distance between the two members at each position and the brightness at each position from the geometric shape based on the acquired image information, and the target region obtained from the acquired image information. A measuring device that converts the brightness of each position in the inside by the correlation to obtain the thickness of the lubricating oil at each position. The imaging device according to claim 1, wherein the imaging device photographs the target region including a region between two members between the first member and the second member that move relative to each other in contact with each other via the lubricating oil. measuring device. The imaging device photographs the target area over time.
The arithmetic device acquires a plurality of the image information from the captured images of the photographing device, and sets the brightness of each position in the target region obtained from one of the plurality of the image information to the one. The measuring device according to claim 1 or 2, wherein the thickness of the lubricating oil at each position is obtained by converting from the correlation obtained from the geometric shape based on the two image information. The target region including the region between the two members between the first member and the second member, which move relative to each other in contact with each other via the lubricating oil, is photographed over time.
The calculation device acquires a plurality of the image information from the captured images taken by the photographing device at different timings, and from each of the acquired plurality of the image information, the correlation at each timing when the captured image is captured is obtained. The measurement according to any one of claims 1 to 3, wherein the thickness of the lubricating oil at each position in the target region at each timing when the captured image is captured is determined and converted by the correlation. apparatus. The arithmetic unit obtains the correlation, and also obtains an estimated correlation between a value larger than the maximum value of the distance between the two members and the brightness in the case of the value, based on the tendency of the correlation, claims 1 to 4. The measuring device according to any one of the above. The imaging device photographs the target area over time.
Any of claims 1 to 5, wherein the arithmetic unit acquires a plurality of the image information from the captured images of the photographing device, obtains the correlation based on each of the plurality of the image information, and determines a change in the correlation. The measuring device according to item 1. It is a measuring method for determining the thickness of the lubricating oil in the first member and the second member whose geometric shapes that come into contact with each other through the lubricating oil containing a fluorescent substance are known.
A step of irradiating a region including a region between two members between the first member and the second member, and a step of irradiating light.
The step of photographing the target area including the area between the two members, and
A step of acquiring image information including the brightness distribution of the target region from the image obtained by the photographing and obtaining the thickness of the lubricating oil in the target region based on the image information.
Including
In the step of obtaining the thickness of the lubricating oil, the correlation between the distance between the two members at each position and the brightness at each position is obtained from the geometric shape based on the acquired image information, and from the acquired image information. A measuring method in which the obtained brightness of each position in the target region is converted by the correlation to obtain the thickness of the lubricating oil at each position.

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