JP2009180716A - Method and device for lubricant coating measurement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant coating measurement device for measuring coating status of lubricant with high accuracy and reliability. <P>SOLUTION: This lubricant coating measurement device includes a light source 40 which irradiates contact portion on a pair of objects with light to generate interference fringe, a spectroscope 36 for generating spectral image of the interference fringe, a microscope 38 for magnifying the spectral image generated by this spectroscope, a high-speed camera 34 for making fast photography of the spectral image magnified by the microscope, a high-speed camera transfer means 46 for moving the high-speed camera along the contact portion, and a computing means 50 for measuring status of oil film from the fast photography data obtained from the high-speed camera. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lubricant coating film measuring method and a lubricant coating film measuring apparatus for measuring the state of a lubricant coating that lubricates a contact portion of a pair of relatively rolling or sliding objects.

For example, in a bearing, the load concentrates when the ball (one object) and the outer ring or inner ring (the other object) lubricated with lubricating oil are in line contact or point contact. The elastic deformation of the oil and the high-pressure viscosity of the lubricating oil must be considered. Such a lubrication state is referred to as an elastohydrodynamic lubrication state (EHL state: Elastohydrodynamic Lubricastion).
As a conventional method for observing the EHL state of such a bearing, a disk-shaped disk and a hard ball are arranged so as to roll or slide relative to each other, and the contact portion of the disk and the hard ball is lubricated with a lubricating oil. In addition, a method is known in which the oil film thickness in the EHL state is measured by a light interference method in which interference oil is generated by irradiating light to the lubricating oil at the contact portion.

However, the measurement of the oil film thickness by the optical interferometry is problematic in terms of accuracy and reliability, and the EHL state cannot be observed with high accuracy.
The present invention has been made to eliminate such inconvenience, and a lubricant capable of observing the EHL state with high accuracy by measuring the coating state of the lubricant with high accuracy and reliability. An object is to provide a coating film measuring method and a lubricant coating film measuring apparatus.

  In order to solve the above problems, the invention according to claim 1 is a method for measuring the thickness of a coating film of a lubricant that lubricates a contact portion of a pair of relatively rolling or sliding objects. Irradiating the contact portion of the coating film with light output from a light source to generate interference fringes, and enlarging a spectral image generated by dispersing the interference fringes while moving along the contact portions A step of performing high-speed photographing, a step of analyzing the luminance distribution of the spectral image based on the high-speed photographed data, and a wavelength of black stripes and light stripes of the spectral image based on the data analyzed of the luminance distribution. A lubricant coating film measuring method comprising: a calculating step; and a step of measuring the thickness of the coating film based on the wavelength of the black stripe and the wavelength of the bright stripe.

Further, the invention of claim 2 is the lubricant coating film measuring method according to claim 1, wherein the light source is a halogen light source and a xenon light source, and light mixed with the halogen light source and the xenon light source is applied to a contact portion of the coating film. I tried to irradiate.
The invention of claim 3 is the lubricant coating film measuring method according to claim 1 or 2, wherein the pair of objects are arranged in an atmosphere state of a specific temperature, and the lubricant is set to a specific temperature. I tried to do it.

According to a fourth aspect of the present invention, in the lubricant coating film measuring method according to any one of the first to third aspects, the pair of objects are pressed against each other.
The invention according to claim 5 is the lubricant coating film measuring method according to any one of claims 1 to 3, wherein a contact portion of one object with the other object of the pair of objects is formed by a spherical surface. Then, while the rotational motion of the motor is converted into the reciprocating swing motion of the one object by the cam mechanism, the one object is slid relative to the other object and the contact portion of the pair of objects is lubricated. The thickness of the lubricant coating was measured.

  On the other hand, the invention of claim 6 is an apparatus for measuring the state of a coating film of a lubricant that lubricates a contact portion of a pair of relatively rolling or sliding objects, and transmits light to the coating film. A light source that irradiates the contact portion to generate an interference fringe, a spectroscope that generates a spectral image of the interference fringe, a microscope that magnifies the spectral image generated by the spectroscope, and the spectrum that is magnified by the microscope A high-speed camera that takes high-speed images, high-speed camera moving means that moves the high-speed camera along the contact portion, and the state of the coating film is measured based on high-speed shooting data obtained from the high-speed camera. And calculating means for analyzing the luminance distribution of the spectral image based on high-speed imaging data, and calculating the spectral image based on the luminance distribution analyzed by the luminance distribution analyzing means. Of black stripe wavelength & bright stripe Wavelength calculating means for calculating the length, and coating film thickness calculating means for calculating the thickness of the coating film based on the wavelength of the black stripe and the wavelength of the bright stripe calculated by the wavelength calculating means. This is a lubricant coating film measuring device characterized by the following.

The seventh aspect of the present invention is the lubricant coating film measuring apparatus according to the sixth aspect, wherein the light source is a halogen light source and a xenon light source, and light mixed with the halogen light source and the xenon light source is applied to the coating film. The contact area was irradiated.
The invention according to claim 8 is the lubricant coating film measuring apparatus according to claim 6 or 7, further comprising torque measuring means for measuring a torque change of at least one of the pair of objects, and the computing means. Is provided with friction coefficient calculating means for calculating the friction coefficient of the contact portion of the pair of objects based on the data measured by the torque measuring means.

The invention according to claim 9 is the lubricant coating film measuring apparatus according to any one of claims 6 to 8, wherein an atmosphere temperature setting means for bringing the pair of objects into an atmosphere state at a specific temperature, and the lubrication And a lubricant temperature setting means for setting the agent to a specific temperature.
According to a tenth aspect of the present invention, in the lubricant coating film measuring apparatus according to any one of the sixth to ninth aspects, a pressing means is provided for pressing the pair of objects against each other.
The invention according to claim 11 is the lubricant coating film measuring apparatus according to any one of claims 6 to 10, wherein a contact portion of one object with the other object of the pair of objects is formed by a spherical surface. And a motor and a cam mechanism for converting the rotational motion of the motor into the reciprocating swing motion of the one object.

According to the lubricant coating film measuring method and the lubricant coating film measuring apparatus of the present invention, the light output from the light source is irradiated onto the contact portion of the coating film to generate interference fringes, while moving along the contact portion, Spectral images generated by spectroscopic interference fringes are magnified and photographed at high speed, the spectral distribution of the spectral distribution is analyzed based on the high-speed captured data, and the wavelength of the black stripes in the spectral image is analyzed based on the analyzed luminance distribution. In addition, the thickness of the coating film is measured based on the wavelength of the black stripe and the wavelength of the bright stripe, and the elastohydrodynamic lubrication has been problematic in terms of accuracy and reliability. The thickness of the coating film of the lubricant in the state (EHL state: Elastohydrodynamic Lubricastion) can be measured with high accuracy and high reliability.
Examples of the measurable lubricant include semi-solid to liquid lubricants. More specifically, in the case of oil (lubricating oil), the oil film thickness can be measured, and in the case of grease (lubricating grease), the grease film thickness can be measured with high accuracy and reliability.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a lubricant coating film measuring apparatus according to the first embodiment of the present invention. Reference numeral 2 denotes a disk-shaped disc test piece made of glass. A disc rotating shaft 6 supported by the apparatus base 4 and extending in the vertical direction is arranged on the axis of the disc test piece 2 facing the vertical direction. The upper part is fixed.

A servo motor 10 is connected to the lower end side of the disk rotation shaft 6 via a timing belt 8, and the driving force of the servo motor 10 rotates around the disk test source 2 via the timing belt 8 and the disk rotation shaft 6. Transmitted as rotation. A first torque meter 12 is connected to the disk rotation shaft 6.
A spherical ball test piece 14 is in contact with the lower surface of the disk test piece 2. A ball connecting shaft 16 extending in the radial direction of the disk test piece 2 is fixed to the ball test piece 14. The ball connecting shaft 16 is supported by a supporting means (not shown) so that the ball test piece 14 made of a steel ball contacts the lower surface of the disk test piece 2.

A servo motor 18 is connected to the ball connecting shaft 16, and the driving force of the servo motor 18 is transmitted as rotation to the ball test piece 14 through the ball connecting shaft 16. A second torque meter 20 is connected to the ball connecting shaft 16.
Reference numeral 22 denotes a lubricant reservoir in which a predetermined amount of lubricating oil is accumulated. The lubricating oil in the lubricant reservoir 22 is heated at a predetermined temperature by a heater (not shown), and the lower side of the ball test piece 14 is immersed in the lubricating oil in the lubricant reservoir 22.

The lubricant reservoir 22 is supported by a load loading device 24 using the lever principle. When a weight 26 having a predetermined weight is placed on the load loading device 24, the side on which the weight 26 is placed is lowered and the weight 26 is placed. As the lubricating oil 22 provided on the opposite side to the fulcrum S rises, the lubricant reservoir 22 presses the ball test piece 14 against the lower surface side of the disk test piece 2.
On the apparatus base 4, a load loading device 24 is arranged so that the lubricant reservoir 22 can move in the X direction (horizontal direction close to or away from the disk rotation shaft 6) or in the Y direction (horizontal direction orthogonal to the X direction). The 1st XY stage 32 which supports is provided.

Reference numeral 28 denotes a chamber in which the disk test piece 2 and the ball test piece 14 are housed, and hot air at a predetermined temperature is supplied into the chamber 28 from a hot air generator 30.
The apparatus base 4 is provided with a second XY stage 44 for moving a unit 42 incorporating a high-speed camera 34, a spectroscope 36, an optical microscope 38, and a light source 40 in the XY direction, and the unit 42 is moved in the X direction. A linear motion device 46 is provided for minute movement. The linear motion device 46 includes a ball screw mechanism 46a and a servo motor 46b that rotates the screw shaft of the ball screw mechanism 46a.

The light source 40 described above is composed of a halogen light source 40a and a xenon light source 40b, and light obtained by mixing the light from the halogen light source 40a and the xenon light source 40b passes through the bifurcated fiber light guide 48 and the objective of the optical microscope 38. The light is irradiated downward from the lens 38a.
A computing device 50 is connected to the high-speed camera 34, and a display device 52 that displays the computation result is connected to the computing device 50.
As shown in FIG. 2, the calculation device 50 includes a luminance distribution analysis circuit 50a, a wavelength calculation circuit 50b, a coating film thickness calculation circuit 50c, a friction coefficient calculation circuit 50d, and a calculation result output circuit 50e.

The luminance distribution analysis circuit 50a is a circuit that analyzes the luminance distribution of a spectral image, which will be described later, based on data obtained from the high-speed camera 34. The wavelength calculation circuit 50b is a circuit that calculates the black stripe wavelength and the bright stripe wavelength of the spectral image based on the luminance distribution analyzed by the luminance distribution analysis circuit 50a. The coating film thickness calculation circuit 50c is a circuit that calculates the thickness of the lubricating oil film at the contact portion of the disk test piece 2 and the ball test piece 14 based on the black stripe wavelength and the bright stripe wavelength calculated by the wavelength calculation circuit 50b. It is.
The friction coefficient calculation circuit 50 d is a circuit that calculates the friction coefficient of the contact portion between the disk test piece 2 and the ball test piece 14 based on the torque change data obtained from the first torque meter 12 and the second torque meter 20. The calculation result output circuit 50e is a circuit that outputs the results calculated by the coating film thickness calculation circuit 50c and the friction coefficient calculation circuit 50d.

  Next, the principle of measuring the thickness of the lubricating oil film that lubricates the contact portion between the disk test piece 2 and the ball test piece 14 will be described with reference to FIGS. FIGS. 5A, 6A, 7A, and 8A are diagrams in which the disk test piece 2 and the ball test piece 14 are stationary, respectively. 5 (b), FIG. 6 (b), FIG. 7 (b), and FIG. 8 (b) are diagrams in a state where the disk test piece 2 and the ball test piece 14 are rotating, respectively.

FIG. 3 is an enlarged view of the contact portion when the glass disk test piece 2 and the ball test piece 14 made of steel balls are stationary, and a Cr semi-permeable film is formed on the lower surface of the disk test piece 2. Further, a spacer film of SiO ₂ is further formed on the lower surface of the Cr semi-permeable film. The light incident from above the disk test piece 2 becomes light R1 reflected by the surface of the Cr semi-transmissive film and light R2 reflected by the surface of the ball test piece 14. Hsio ₂ is the thickness of the spacer film of SiO ₂ , and hgap is the thickness of the gap caused by the surface roughness.

FIG. 4 is an enlarged view showing a state where the disk test piece 2 and the ball test piece 14 are rotated, and a lubricating oil film is formed between the contact portions of the disk test piece 2 and the ball test piece 14. Is formed. hoil is the thickness of the lubricating oil film. Since the lights R1 and R2 cause interference, a Newton ring (interference fringes) as shown in FIG. 5 is observed. FIG. 5 shows the interference fringes in a simplified manner.
Then, a spectral image of the region along the line A of the interference fringes in FIG. 5 is obtained, and the spectral image is enlarged and photographed at a high speed to obtain the image shown in FIG. FIG. 6 also shows a simplified image taken at high speed.

Next, the luminance distribution in the region along the line B of the spectral image obtained in FIG. 6 is analyzed, and the analysis diagram shown in FIG. 7 is obtained. That is, in FIG. 7A, the wavelength λ1 of the dark fringe of the interference fringe and the wavelength λ2 of the bright fringe when stationary are calculated, and in FIG. 7B, the wavelength λ3 of the dark fringe of the interference fringe during rotation. The wavelength λ4 of the bright stripe is calculated.
Here, from the relationship between the optical path difference of the light R1 and R2 and the light and darkness of the interference fringes, the following formula is established from the wavelength λ1 and the light fringe wavelength λ2 of the interference fringes at rest. Note that noil is the refractive index of the lubricating oil.
Dark stripes: (2noil (hsio ₂ + hgap)) / λ1 = m ………………… Equation 1
Light stripes: (2noil (hsio ₂ + hgap)) / λ2 = m + 1/2 ......... Formula 2
Further, the following expressions are established based on Expressions 1 and 2.
hsio ₂ + hgap = (λ1λ2) / (4noil (λ1−λ2))...

As described above, the thickness (hsio ₂ + hgap) obtained by adding the thickness of the spacer film and the gap caused by the surface roughness is calculated from the wavelength λ1 of the dark fringe and the wavelength λ2 of the bright fringe at rest. FIG. 8A shows the result of plotting the value of hsio ₂ + hgap.
Further, the following expression is established from the wavelength λ3 of the dark fringe and the wavelength λ4 of the bright fringe during rotation.
hoil + hsio ₂ + hgap
= (Λ3λ4) / (4noil (λ3−λ4) ......... Formula 4

FIG. 8B shows the result of plotting the values of foil + hsio ₂ + hgap.
Then, the thickness hoil of the lubricating oil film when the disc test piece 2 and the ball test piece 14 are rotating is obtained based on the formulas 3 and 4 as follows.
hoil = (1 / 4noil) ((λ3λ4) / (λ3-λ4) − (λ1λ2) / (λ1-λ2)...

Next, the lubricating oil film measuring method using the lubricant coating film measuring apparatus 1 of the present embodiment will be described together with the operation.
First, a method for measuring the thickness of the lubricating oil film at the contact portion between the disk test piece 2 and the ball test piece 14 using the lubricant coating film measuring apparatus 1 will be described.
The unit 42 is moved in the horizontal direction by driving the second XY stage 44, and the objective lens 38 a of the optical microscope 38 is positioned above the contact portion between the disk test piece 2 and the ball test piece 14.

  Next, a weight 26 having a predetermined weight is placed on the load application device 24, and the ball test piece 14 is pressed against the lower surface side of the disk test piece 2 by the lubricant reservoir 22 in which the lower side of the ball test piece 14 is immersed. In addition, the lubricating oil in the lubricant reservoir 22 is heated to a predetermined temperature, and hot air at a predetermined temperature is supplied from the hot air generator 30 into the chamber in which the disk test piece 2 and the ball test piece 14 are housed. .

Thus, a pressing force is generated between the ball test piece 14 and the disk test piece 2 by the load application device 24, and the ball test piece 14 and the disk test piece 2 are brought into contact with each other at a predetermined atmospheric temperature by the hot air generation device 30. Furthermore, since the lubricating oil is also set at a predetermined temperature, highly reproducible measurement is performed.
Then, measurement is started with the disk test piece 2 and the ball test piece 14 being stationary.

Light obtained by mixing the light from the halogen light source 40a and the light from the xenon light source 40b is applied to the contact portion of the disk test piece 2 and the ball test piece 14 to generate interference fringes at the contact portion (see FIG. 5A). .
Here, the light obtained by mixing the light from the halogen light source 40a and the light from the xenon light source 40b is special light having a wide wavelength range and high luminance.

The spectroscope 36 generates a spectral image of interference fringes, and the high-speed camera 34 takes a high-speed image of the spectral image magnified by the optical microscope 38. Thus, when the high-speed camera 34 takes a spectral image at high speed, the linear motion device 46 slightly moves the unit 42 in the X direction (see FIG. 6A).
As described above, the high-speed camera 34 takes a high-speed image of the spectral image while moving it in the direction of the unit 42X by the linear motion device 46, so that the contact portion between the disk test piece 2 and the ball test piece 14 at a stationary time is wide. Is taken with high accuracy.

Data taken by the high-speed camera 34 at high speed is input to the luminance distribution analysis circuit 50a of the arithmetic device 50. The luminance distribution analysis circuit 50a analyzes the luminance distribution of the spectral image to obtain analysis data. Then, the wavelength calculation circuit 50b calculates the dark fringe wavelength λ1 and the bright fringe wavelength λ2 of the interference fringes based on the data analyzed by the luminance distribution analysis circuit 50a (see FIG. 7A). .
Then, the disk test piece 2 is rotated by driving the servo motor 10, and the ball test piece 14 is rotated by driving the servo motor 18. At this time, since the lower side of the ball test piece 14 is immersed in the lubricant reservoir 22, the lubricating oil is sequentially supplied between the disk test piece 2 and the ball test piece 14 to form a lubricating oil film ( (See FIG. 4). Then, measurement of the lubricating oil film is started.

That is, the light which mixed the light of the halogen light source 40a and the light of the xenon light source 40b is irradiated to the contact part of the disk test piece 2 and the ball test piece 14, and an interference fringe is generated in the contact part ((b) of FIG. 5). reference).
Then, the high-speed camera 34 captures a spectral image magnified by the optical microscope 38 at high speed. Also in this case, the linear motion device 46 slightly moves the unit 42 in the X direction (see FIG. 6B).

In this way, the high-speed camera 34 captures a spectral image at a high speed while moving the micro-movement in the unit 42X direction by the linear motion device 46, so that the contact portion between the disk test piece 2 and the ball test piece 14 during rotation is wide. Is taken with high accuracy.
The luminance distribution analysis circuit 50 a of the arithmetic device 50 obtains analysis data based on the high-speed shooting data input from the high-speed camera 34. Then, the wavelength calculation circuit 50b calculates the dark fringe wavelength λ3 and the bright fringe wavelength λ4 of the interference fringes based on the data analyzed by the luminance distribution analysis circuit 50a (see FIG. 7B). .

The coating film thickness calculation circuit 50c is based on the interference fringe dark stripe wavelength λ1, the bright stripe wavelength λ2, the interference fringe dark stripe wavelength λ3, and the bright stripe wavelength λ4 when rotated. Is calculated (see FIG. 8B).
Then, the calculation result output circuit 50e outputs the lubricating film thickness hoil calculated by the coating film thickness calculation circuit 50c to the display device 52.
Thereby, the measurement of the thickness of the lubricating oil film at the contact portion between the disk test piece 2 and the ball test piece 14 is completed.

Next, a method for measuring the thickness of the lubricating oil film at the contact portion between the disk test piece 2 and the ball test piece 14 using the lubricant coating film measuring apparatus 1 will be described.
The first torque meter 12 measures the torque change of the disk rotating shaft 6 when the disk test piece 2 is rotating, and the second torque meter 20 is the ball connecting shaft when the ball test piece 14 is rotating. The torque change data of the first and second torque meters 12 and 20 is input to the friction coefficient calculation circuit 50d of the calculation device 50.

The friction coefficient calculation circuit 50d calculates the friction coefficient of the contact portion between the disk test piece 2 and the ball test piece 14 based on the input torque change on the disk test piece 2 side and the ball test piece 14 side.
Then, the calculation result output circuit 50e outputs the friction coefficient of the contact portion between the disk test piece 2 and the ball test piece 14 calculated by the friction coefficient calculation circuit 50d to the display device 52.
Thereby, the measurement of the friction coefficient of the contact part of the disk test piece 2 and the ball test piece 14 is completed.

  The disk test piece 2 and the ball test piece 14 correspond to a pair of objects of the present invention, the optical microscope 38 corresponds to the microscope of the present invention, and the linear motion device 46 corresponds to the high-speed camera moving means of the present invention. The calculation device 50 corresponds to the calculation means of the present invention, the luminance distribution analysis circuit 50a corresponds to the luminance distribution analysis means of the present invention, the wavelength calculation circuit 50b corresponds to the wavelength calculation means of the present invention, and the coating thickness. The calculation circuit 50c corresponds to the coating film thickness calculation means of the present invention, the first torque meter 12 and the second torque meter 20 correspond to the torque measurement means of the present invention, and the friction coefficient calculation circuit 50d corresponds to the friction coefficient of the present invention. The chamber 28 corresponds to the atmospheric temperature setting means of the present invention, and the lubricant reservoir 22 and the load load device 24 correspond to the pressing means of the present invention.

  Accordingly, in the present embodiment, the light output from the light source 40 is applied to the lubricating oil film at the contact portion between the disk test piece 2 and the ball test piece 14 to generate interference fringes, and the linear motion device 46 causes the unit 42 to be X While moving in the direction, the spectral image of the interference fringes generated by the spectroscope 36 is magnified by the optical microscope 38 while being photographed at high speed by the high-speed camera 34, and the thickness of the lubricating oil film is measured based on the high-speed photographed data. Therefore, the thickness of the lubricating oil film in the elastohydrodynamic lubrication state (EHL state: Elastohydrodynamic Lubricastion), which has conventionally been problematic in terms of accuracy and reliability, can be performed with high accuracy and high reliability. it can.

The light from the light source 40 is a light obtained by mixing the light from the halogen light source 40a and the light from the xenon light source 40b, and has a wide wavelength range and has a high luminance, and thus generates interference fringes. The thickness of the lubricating oil film can be measured with higher accuracy.
Further, a pressing force is generated between the ball test piece 14 and the disk test piece 2 by the load loading device 24, the ball test piece 14 and the disk test piece 2 are contacted at a predetermined atmospheric temperature by the hot air generation device 30, and Since the lubricating oil is also set to a predetermined temperature, highly reproducible measurement can be performed.

  Furthermore, the torque change of the disk rotating shaft 6 when the disk test piece 2 is rotated by the first torque meter 12 is measured, and the ball connecting shaft when the ball test piece 14 is rotated by the second torque meter 20. 16, the friction coefficient calculation circuit 50 d of the calculation device 50 is in contact with the disk test piece 2 and the ball test piece 14 based on the torque change data of the first and second torque meters 12 and 20. Therefore, the friction coefficient of the contact portion between the disk test piece 2 and the ball test piece 14 can be measured with a simple configuration.

(Second Embodiment)
Next, FIG. 9 is a diagram showing a lubricant coating film measuring apparatus according to a second embodiment of the present invention having a configuration different from that of FIG.
The lubricant coating film measuring device 58 of the present embodiment has a rubber spatula in which a predetermined amount of grease is collected in the lubricant reservoir 22 and the grease applied to the lower surface of the disk test piece 2 is scraped off on the device mount 4. A scraping portion 60 made of the like or the like is provided. The scraping portion 60 is close to the lower surface of the disk test piece 2 and scrapes off excess amount of grease applied to the lower surface of the disk test piece 2 from the lubricant reservoir 22 via the ball test piece 14 during the test. The thickness of the coating film of grease existing on the lower surface of the disk test piece 2 is made constant. By doing in this way, the formation capability of the coating film of the grease on the lower surface of the disk test piece 2 can be performed with high accuracy.

And this embodiment also performs the same procedure as the method of measuring the thickness of the lubricating oil film using the lubricating oil, so that the conventional elastohydrodynamic lubrication state (EHL state) has been problematic in terms of accuracy and reliability. : Elastohydrodynamic Lubricastion) grease coating thickness can be measured with high accuracy and high reliability.
(Third embodiment)
FIG. 10 is a diagram showing a configuration of the lubricant coating film measuring apparatus according to the third embodiment of the present invention. In addition, in the lubricant coating film measuring apparatus 70 of this embodiment, the same code | symbol is attached | subjected about the same part as the lubricant coating film measuring apparatus 1 of 1st embodiment, and description is abbreviate | omitted.

The lubricant coating film measuring device 70 of this embodiment is different from the lubricant coating film measuring device 1 shown in FIG. 1 in place of the second torque meter 20 and the servo motor 18 in the lubricant coating film measuring device 1. A cam mechanism 72 and a servo motor 74 are provided.
As shown in FIG. 11, the cam mechanism 72 includes a columnar eccentric cam 76 connected to the rotation shaft 75 of the servo motor 74 and a crank 78 connected to the eccentric cam 76. The eccentric cam 76 has an axis SC parallel to the axis SM of the rotating shaft 75. However, the shaft center SM of the eccentric cam 76 is separated from the shaft center SC of the rotating shaft 75 by a predetermined distance E, and this distance E is the amount of eccentricity of the eccentric cam 76.

  The eccentric cam 76 is coaxially formed with a shaft 77 having a circular cross section at the center in the axial direction. On the other hand, the crank 78 is formed in a plate shape elongated in the vertical direction, and a circular bearing hole 79 is formed in the lower end side thereof. In the cam mechanism 72, the shaft portion 77 of the eccentric cam 76 is inserted into the bearing hole 79 of the crank 78 so as to be relatively rotatable. Further, the base end portion of the ball connecting shaft 16 is connected to the upper end portion of the crank 78 via a joint member 80 such as a ball joint. Thereby, the ball rotating shaft 75 is connected to the crank 78 so as to be swingable along the vertical direction.

  In the cam mechanism 72, the eccentric amount E of the eccentric cam 76 can be adjusted. As an adjustment method, for example, a plurality of eccentric cams 76 having different eccentric amounts E are prepared in advance, and the eccentric cam 76 having a desired eccentric amount E is attached to the rotary shaft 75 before the test by the apparatus is started. Thus, the eccentric amount E is adjusted. Further, an adjustment mechanism (not shown) for adjusting the eccentric amount E may be provided in the eccentric cam 76, and the eccentric amount E may be adjusted by this adjusting mechanism.

  As shown in FIG. 12, a servo control circuit 82 is provided in the arithmetic circuit 50 of the lubricant coating film measuring device 70. The servo control circuit 82 outputs a servo drive signal to the servo motor 74 during operation of the apparatus, and outputs a feedback signal corresponding to the rotation speed of the servo motor 74 to the calculation result output circuit 50e. As a result, the servo motor 74 rotates at a rotation speed corresponding to the servo drive signal and outputs a feedback signal to the servo control circuit 82. The calculation result output circuit 50e calculates the rotational speed of the servo motor 74 based on the feedback signal and outputs the display signal to the display device 52.

Next, a description will be given of the relationship between the swing amount of the amplitude ratio A _R and ball test piece 14 of the cam mechanism 72. FIGS. 13A to 13D show the amplitude amount of the ball test piece 14 when the ball connecting shaft 16 is assumed to be directly connected to the crank 78 without using the joint member 80 (hereinafter referred to as “amplitude amount”). The relationship between the “virtual amplitude amount”) and the amplitude ratio AR is shown. Here, as shown in FIG. 13A, the amplitude ratio AR of the cam mechanism 72 is expressed by B / E when the radius of the ball test piece 14 is B and the eccentric amount E of the eccentric cam 76. It is a numerical value.

  When the amplitude ratio AR is less than 1, the virtual amplitude amount of the ball test piece 14 is smaller than the diameter (B × 2) of the ball test piece 14 as shown in FIG. When AR is 1, as shown in FIG. 13C, the virtual amplitude amount of the ball test piece 14 is equal to the diameter (B × 2) of the ball test piece 14, and the amplitude ratio AR is 1. When exceeding, as shown in FIG. 13D, the virtual amplitude amount of the ball test piece 14 becomes larger than the diameter (B × 2) of the ball test piece 14.

  On the other hand, in the actual cam mechanism 72, since the base end portion of the ball connecting shaft 16 is connected to the crank 78 via the joint member 80, the ball test piece 14 is proportional to the magnitude of the virtual amplitude. A rocking motion of a rocking amount will occur. At this time, since one cycle of the swinging motion of the ball test piece 14 is synchronized with one rotation of the servo motor 74, the frequency of the swinging motion of the ball test piece 14 matches the rotational speed of the servo motor 74.

In the lubricant coating film measuring apparatus 70 described above, when measuring the thickness of the lubricating oil film, the servomotor 74 is rotated to swing the ball test piece 14 to the lubricating oil film on the disk test piece 2. In contrast, an unsteady state can be obtained.
Therefore, in the lubricant coating film measuring apparatus 70, the thickness of the lubricating oil film in the elastohydrodynamic lubrication state (EHL state: Elastohydrodynamic Lubricastion) is accurately determined, as in the lubricant coating film measuring apparatus 1 of the first embodiment. In addition to being able to measure with high reliability, the thickness of the lubricating oil film can be measured with high accuracy while the ball test piece 14 is in an unsteady state in which it swings at a predetermined swing amount and frequency.

As a swing mechanism for swinging the ball test piece 14 at a predetermined swing amount and frequency, for example, the rotation shaft of the servo motor is arranged so as to be orthogonal to the ball connecting shaft 16, and the rotation shaft of the servo motor is It is also conceivable that the servo motor is controlled to repeat normal rotation and reverse rotation by directly connecting to the base end portion of the ball connecting shaft. However, with such a swinging mechanism, it is difficult to set the amplitude ratio AR to 5 or less, and the ball test piece 14 is easily affected by the inertia of the ball test piece 14. It is difficult to swing with the amount of movement.
In the present embodiment, the minimum amplitude ratio AR is set to 0.55. However, by attaching an eccentric cam 76 having a smaller eccentricity E to the servo motor 74, the amplitude ratio AR is further set to be less than 0.55. It is also possible to make it smaller.

Next, the result of measuring the thickness of the lubricating oil film using the lubricant coating film measuring apparatus 70 according to the third embodiment of the present invention will be described as an example.
14A to 14D show the results of measuring the thickness of the lubricating oil film along the X-axis direction while changing the swing amount of the ball test piece 14 stepwise.
FIG. 14A shows the measurement result for the thickness of the lubricating oil film while the ball test piece 14 is swung with the amplitude ratio AR set to 0.55. FIG. 14B shows the measurement results for the thickness of the lubricating oil film while the ball test piece 14 is swung while the amplitude ratio AR is set to 1.29. FIG. 14C shows the measurement result for the thickness of the lubricating oil film while the ball test piece 14 is swung while the amplitude ratio AR is set to 1.29. FIG. 14D shows the measurement results for the thickness of the lubricating oil film while the ball test piece 14 is swung while the amplitude ratio AR is set to 1.98.

It is a figure which shows the lubricant coating-film measuring apparatus of 1st Embodiment which concerns on this invention. It is a figure which shows the structure of the calculating means which comprises the lubricant film measuring apparatus of 1st Embodiment which concerns on this invention. It is the figure which expanded and showed the contact part of a pair of object at the time of a rest. It is the figure which expanded and showed the contact part of a pair of object at the time of rotation. It is a figure which shows the outline of the interference fringe generated by irradiating light. It is a figure which shows the outline of the image which image | photographed the spectral image at high speed. It is the analysis figure which carried out the luminance analysis of the spectral image. It is a figure which shows the result of having measured the thickness of the oil film. It is a figure which shows the lubricant film measuring apparatus of 2nd Embodiment which concerns on this invention. It is a figure which shows the lubricant film measuring apparatus of 3rd Embodiment which concerns on this invention. It is a figure which shows the cam mechanism and servomotor in the lubricant coating-film measuring apparatus shown by FIG. It is a figure which shows the structure of the calculating means which comprises the lubricant film measuring apparatus of 3rd Embodiment which concerns on this invention. It is a figure which shows the relationship between the amplitude ratio of the eccentric cam in the cam mechanism shown by FIG. 10, and the amplitude amount of a ball test piece. It is a figure which shows the result which measured the thickness of the lubricating oil film along the X-axis direction, changing the rocking | fluctuation amount of a ball test piece in steps using the lubricant coating film measuring apparatus shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lubricant coating film measuring device 2 Disc test piece 10 Servo motor 12 First torque meter 14 Ball test piece 18 Servo motor 20 Second torque meter 22 Lubricant reservoir 24 Load loading device 28 Chamber 34 High speed camera 36 Spectrometer 38 Optical Microscope 40 Light source 40a Halogen light source 40b Xenon light source 42 Unit 44 2nd XY stage 46 Linear motion device 50 Arithmetic device 50a Luminance distribution analysis circuit 50b Wavelength computation circuit 50c Coating film thickness computation circuit 50d Friction coefficient computation circuit 52 Display device 58 Lubricant coating Film measuring device 60 Scraping portion 70 Lubricant coating film measuring device 72 Cam mechanism 74 Servo motor 75 Rotating shaft 76 Eccentric cam 77 Shaft portion 78 Crank 80 Joint member 82 Servo control circuit

Claims (11)

A method of measuring the thickness of a coating film of a lubricant that lubricates a contact portion of a pair of relatively rolling or sliding objects,
Irradiating the contact portion of the coating film with light output from a light source to generate interference fringes;
A step of enlarging a spectral image generated by spectrally separating the interference fringes while moving along the contact portion, and high-speed imaging;
Analyzing the luminance distribution of the spectral image based on high-speed photographed data;
A step of calculating the wavelength of black stripes and the wavelength of bright stripes of the spectral image based on data obtained by analyzing the luminance distribution;
And a step of measuring the thickness of the coating film based on the wavelength of the black stripes and the wavelength of the bright stripes.   2. The method of measuring a lubricant coating film according to claim 1, wherein the light source is a halogen light source and a xenon light source, and the contact portion of the oil film is irradiated with light obtained by mixing the halogen light source and the xenon light source.   The lubricant coating film measuring method according to claim 1 or 2, wherein the pair of objects are arranged in an atmosphere state of a specific temperature, and the lubricant is set to a specific temperature.   The lubricant coating film measuring method according to any one of claims 1 to 3, wherein the pair of objects are pressed against each other. A contact portion of one object in the pair of objects with the other object is formed by a spherical surface,
While the rotational movement of the motor is converted into the reciprocating swinging motion of the one object by the cam mechanism, the one object is slid relative to the other object and the contact portion of the pair of objects is lubricated. The method for measuring a lubricant coating film according to any one of claims 1 to 4, wherein the thickness of the coating film of the lubricant is measured. A device that measures the state of a coating film of a lubricant that lubricates a contact portion of a pair of relatively rolling or sliding objects,
A light source that generates interference fringes by irradiating the contact portion of the coating film with light,
A spectroscope for generating a spectral image of the interference fringes;
A microscope for enlarging the spectral image generated by the spectrometer;
A high-speed camera for high-speed imaging of the spectral image magnified by this microscope,
High-speed camera moving means for moving the high-speed camera along the contact portion;
Computation means for measuring the state of the coating film based on high-speed shooting data obtained from the high-speed camera,
The calculation means includes a luminance distribution analysis means for analyzing the luminance distribution of the spectral image based on high-speed imaging data, and the black stripe wavelength and bright stripes of the spectral image based on the luminance distribution analyzed by the luminance distribution analysis means. Wavelength calculating means for calculating the wavelength of the coating film, and coating film thickness calculating means for calculating the thickness of the coating film based on the wavelength of the black stripe and the wavelength of the bright stripe calculated by the wavelength calculating means. Lubricant coating film measuring device characterized by that.   7. The lubricant coating film measuring apparatus according to claim 6, wherein the light source is a halogen light source and a xenon light source, and light mixed with the halogen light source and the xenon light source is irradiated to a contact portion of the coating film. .   Torque measurement means for measuring a torque change of at least one of the pair of objects is provided, and the calculation means calculates a friction coefficient of a contact portion of the pair of objects based on data measured by the torque measurement means. 8. The lubricant coating film measuring apparatus according to claim 6, further comprising a friction coefficient calculating means for calculating.   9. The apparatus according to claim 6, further comprising: an ambient temperature setting unit that sets the pair of objects in an atmospheric state at a specific temperature; and a lubricant temperature setting unit that sets the lubricant to a specific temperature. The lubricant coating film measuring apparatus according to the item.   10. The lubricant coating film measuring apparatus according to claim 6, further comprising a pressing unit configured to press the pair of objects against each other. A contact portion of one object in the pair of objects with the other object is formed by a spherical surface,
The lubricant according to any one of claims 6 to 10, further comprising a motor and a cam mechanism that converts a rotational motion of the motor into a reciprocating swing motion of the one object. Coating film measuring device.

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