JP6500876B2 - Sliding device - Google Patents

Description

  The present invention relates to a sliding device that visualizes a sliding surface.

  The sliding device is a device that evaluates the characteristics of the sliding surface by measuring the coefficient of friction, the amount of wear, etc. of the sliding interface. As a general evaluation process, observation and analysis of a sliding surface are performed after a sliding test, and the mechanism in which the said sliding characteristic is obtained is analyzed. Visualization of the sliding interface is effective in such mechanism analysis. This is because visualization enables in-situ observation of the sliding surface and various measurements (oil film measurement and temperature measurement) on the spot. In fact, in the research and development of sliding parts, visualization and measurement of the sliding interface are performed by various methods.

  One of the general sliding surface shapes of the sliding body used for the machine element is a rotationally symmetrical shape. Generally, sliding surfaces are required to have high standards for their geometrical tolerances and surface roughness, but machining using rotational motion such as lathe processing has high accuracy and it is easy to meet those requirements. It is from. Even if it is limited to sliding bodies used in automobiles, there are many such as inner rings, outer rings, balls and rollers of rolling bearings, sliding bearings, crankshafts, piston bores, pulleys of belts CVT, gears, clutch friction materials, tires and the like.

  Here, there is also a case where not all of the sliding surfaces constituting the sliding interface have a rotationally symmetrical shape. For example, in the case of a pulley of a belt CVT, the sliding surface of the pulley is rotationally symmetrical, but the sliding surface of the element which is the opposite member is not rotationally symmetrical. Moreover, in the case of a tire, the sliding surface of the road surface which is the opposite material is not rotationally symmetrical.

  The forms of relative movement of the sliding surface include rotational sliding motion (sliding bearing, crankshaft, gear, pulley, clutch friction material, etc.) and reciprocating sliding motion (piston and bore, etc.), rolling motion (inner and outer rings of rolling bearing) And balls, tires, gears etc.).

  From this background, visualizing the sliding interface composed of the rotationally symmetric sliding surface is useful for the sliding mechanism analysis in the mechanical element.

  As such, visualization of the sliding interface composed of the rotationally symmetric sliding surface is useful, so there are many patent documents and non-patent documents related thereto. An example is shown below.

  In the oil film visualization device described in Patent Document 1, the crankshaft is made of a transparent material (acrylic) in rotational sliding sliding of the crankshaft-sliding bearing of the internal combustion engine main bearing portion, and the sliding bearing in the sliding bearing faces obliquely. The sliding bearing sliding surface is observed by detecting the reflected light through the transparent crank shaft and using a camera located outside the transparent crank shaft. However, in this apparatus, unlike the actual machine, the crankshaft does not rotate, but only reciprocates in the radial direction, and the occurrence of cavitation due to oil film pressure fluctuation is observed. Therefore, it is not a sliding device.

  In Non-Patent Document 1, the outer ring is made of a transparent body (sapphire) in the rolling and sliding of the outer ring and the ball of the rolling bearing, and light emitted from the sliding interface of the outer ring and the ball is transmitted through the transparent outer ring. It is detected by a camera located outside the transparent outer ring, and oil film measurement is performed.

  In Non-Patent Document 2, in the reciprocating sliding of the piston-bore of an internal combustion engine, the bore is made of a transparent material (glass), light emitted from the piston sliding surface is transmitted through the transparent bore, and the transparent bore is produced. The piston sliding surface is observed and oil film measured by detecting with a detector located outside of.

Patent No. 5727182 gazette

M. Chennauoi, M. Fowell, A. Kadiric: “In-situ Measurement of Oil Films in a Model Rolling Bearing”, Proceedings of International Tribology Conference TOKYO 2015, 17pE-03 Thermal Energy Engineering Laboratory, Faculty of Engineering, Tottori University "Influence of piston skirt shape on lubricating oil film behavior"

  Although the device of Patent Document 1 is not a sliding device, it is easy to provide a sliding mechanism by improvement, so the problem in the case where the transparent crankshaft and the sliding bearing are slid by this device will be considered. In this case, although the sliding bearing sliding surface to be observed is observed through the acrylic axis, it is noise due to the near side sliding interface that can be mentioned as a problem first. Specifically, in the apparatus configuration of Patent Document 1, sliding interfaces exist on two surfaces on the front side and the rear side (observation target) on the optical path of the camera, and the light captured by the detector slides on two surfaces. It is the sum of light emitted from the moving interface. At the sliding interface on the front side, although the axis is made of a transparent material, “reflection of light due to difference in refractive index between acrylic axis and oil film” and “scattering of light due to surface roughness of acrylic axis” occur Therefore, they become noises and adversely affect observation and measurement of the target sliding surface.

  In the non-patent document 1, the sliding interface between the outer sides of the transparent rotationally symmetric sliding body can not be visualized because of the device configuration in which the counterpart sliding body (ball) is inside the transparent rotationally symmetric sliding body (outer ring).

  Further, in Non-Patent Document 2, as in Non-Patent Document 1, there is a mating sliding body (piston) inside the transparent rotationally symmetric sliding body (bore), so the sliding interface between the outer sides of the transparent rotationally symmetric sliding body Can not be visualized.

  In order to solve the problem that light emitted from the sliding surface of the mating sliding member located outside the sliding surface of the transparent rotationally symmetric sliding member can not be detected, the inner sliding member (the inner ring of Non Patent Literature 1, Non Patent It is necessary to configure the sliding surface of the piston in the document 2) with a transparent body, and install a light detector further inside. However, assuming the size of the sliding body in a general sliding device, the space inside the sliding surface is not sufficient for the size of the light detector, the lens, etc., so installation is difficult. This is a problem unique to the case where the sliding surface has a rotationally symmetric shape, and such a problem does not occur if the sliding surface is flat.

  In addition, when light emitted from the sliding surface of the mating sliding body located outside the sliding surface of the transparent rotationally symmetrical sliding body is detected, the problem of noise getting on because of passing through two or more sliding interfaces is solved. In order to do this, it is necessary to install a light detector inside the sliding surface of the transparent rotationally symmetric sliding body, which is difficult.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a sliding device capable of visualizing a sliding surface between a transparent rotationally symmetrical sliding member and a mating sliding member with reduced noise. Is the purpose.

  A sliding device according to the present invention is a sliding device comprising a first sliding body, a second sliding body, a light reflector or a lens having a light reflecting function, and a light detector, wherein the first sliding body And the second sliding body slide relative to each other to form a sliding interface, and the sliding surface of the first sliding body with the second sliding body is made of a material that transmits light, The shape of the sliding surface of the first sliding body with the second sliding body is a rotationally symmetrical shape or a shape obtained by cutting out a part of the rotationally symmetrical shape, and the sliding of the first sliding body with the second sliding body The sliding surface of the second sliding member exists outside the surface, and the light reflector or the light reflecting function is provided inside the sliding surface of the first sliding member with the second sliding member. A lens is present, and emitted from the sliding surface of the second sliding body with the first sliding body, to the first sliding body The light transmitted through the sliding surface with the second sliding body is reflected by the light reflector or the lens having the light reflecting function, and the light detector detects the reflected light; The light emitted from the sliding surface of the second sliding body with the first sliding body does not pass through two or more sliding interfaces in the optical path until it is detected by the light detector. I assume.

  In the sliding device according to the present invention, when the first sliding body and the second sliding body slide relative to each other to form a sliding interface, the second sliding body slides with the first sliding body The light emitted from the surface and transmitted through the sliding surface of the first sliding member with the second sliding member is reflected by the light reflector or the lens having the light reflecting function. The light detector then detects the reflected light. At this time, light emitted from the sliding surface of the second sliding body with the first sliding body does not pass through two or more sliding interfaces in the optical path until it is detected by the photodetector.

  As described above, the light emitted from the sliding surface of the second sliding body with the first sliding body does not pass through two or more sliding interfaces in the optical path until it is detected by the light detector. By suppressing the noise, it is possible to visualize the sliding surface between the transparent rotationally symmetrical sliding member and the other mating sliding member.

  The shape of the light reflection surface of the light reflector or the shape of the light reflection surface of the lens having the light reflection function in the present invention is emitted from the sliding surface of the second sliding body with the first sliding body. And the light transmitted through the sliding surface of the first sliding body with the second sliding body is shaped to be reflected toward the light detector over the entire surface of the sliding face. It can be characterized. In addition, the shape of the light reflection surface of the light reflector or the shape of the light reflection surface of the lens having the light reflection function may be a rotationally symmetric shape or a shape in which a part of the rotationally symmetric shape is cut out. It can be characterized. Thereby, the entire surface of the sliding surface can be visualized in one shot.

  The rotationally symmetric shape of the sliding surface of the first sliding body with the second sliding body has the largest radius in all the cross sections when the sliding surface is viewed in a cross section orthogonal to the rotation axis of the rotationally symmetric shape. It can be characterized by being 250 mm or less. The rotationally symmetric shape of the sliding surface of the first sliding body with the second sliding body is the maximum in all the cross sections when the sliding surface is viewed in a cross section orthogonal to the rotation axis of the rotationally symmetric shape. The radius may be 100 mm or less. This makes it possible to visualize the sliding surface even if the radius of the rotationally symmetric shape of the sliding surface is so small that the light detector can not be disposed inside.

  The rotationally symmetrical shape of the sliding surface of the first sliding body with the second sliding body is the maximum central angle in all the cross sections when the rotationally symmetrical shape is viewed in a cross section orthogonal to the rotational axis of the rotationally symmetric shape. Can be characterized by being 10 degrees or more. Further, the rotationally symmetrical shape of the sliding surface of the first sliding body with the second sliding body is the maximum in all the cross sections when the rotationally symmetrical shape is viewed in a cross section orthogonal to the rotation axis of the rotationally symmetrical shape. The central angle may be 30 degrees or more. Thus, even if the central angle of the rotationally symmetric shape of the sliding surface is large, the sliding surface can be visualized in one shot.

  The shape of the sliding surface of the first sliding body with the second sliding body may be a continuous rotational symmetry shape or a shape obtained by cutting out a portion of the continuous rotational symmetry shape. .

  The shape of the sliding surface of the first sliding body with the second sliding body may be a cylindrical shape or a shape obtained by cutting out a part of the cylindrical shape.

  The lens with the light reflecting function can have a toric refractive surface.

  The light reflecting surface of the lens having the light reflecting function may have a convex aspheric shape or a shape in which a part of the convex aspheric shape is cut away. Thus, light emitted from the entire surface of the sliding surface of the second sliding member with the first sliding member and transmitted through the sliding surface of the first sliding member with the second sliding member is directed to the light detector. It can be reflected.

  As described above, in the sliding device according to the present invention, the sliding interface in the light path until the light emitted from the sliding surface of the second sliding member with the first sliding member is detected by the light detector. Since it does not pass through two or more surfaces, it has an excellent effect that noise can be suppressed and the sliding surface between the transparent rotational symmetric sliding member and the other opposing sliding member can be visualized.

(A) A drawing for explaining a sliding surface of continuous rotational symmetry shape, (B) A drawing for explaining a sliding surface of discrete rotation symmetry shape, and (C) A part of the rotation symmetrical shape is cut. It is a figure for demonstrating the missing sliding surface. It is a figure showing the composition of the sliding face visualization system concerning the embodiment of the present invention. It is a perspective view which shows an example of a transparent rotation-symmetrical sliding body. It is a perspective view which shows an example of the other party sliding body. It is a perspective view showing composition of an optical system of a sliding face visualization system concerning an embodiment of the present invention. It is sectional drawing which shows the structure of the lens with a reflection function. It is a graph which shows the light emission time of a xenon flash lamp. It is a figure which shows an example of the image imaged with the photodetector. It is a figure which shows the other example of a structure of the sliding surface visualization system which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Definition of terms>
Prior to the description of the embodiment of the present invention, each term is defined.

<Rotally symmetrical shape>
The embodiment of the present invention relates to a sliding device in which at least one sliding surface has a rotationally symmetrical shape (the sliding body itself does not have to be a rotationally symmetrical shape, and the "sliding surface" of the sliding body is It may be a rotationally symmetrical shape). Here, the rotationally symmetric shape means two of a shape having "continuous rotational symmetry" and a shape having "discrete rotational symmetry". A shape having continuous symmetry is a shape in which symmetry is continuously (always) maintained when the shape is rotated 360 ° with respect to a certain axis (FIG. 1A). reference). In other words, when an arbitrary two-dimensional shape is rotationally moved with respect to a certain axis, it is a shape that can be obtained by its trajectory. Specifically, the shape is a sphere, a cylinder, a tapered cylinder, a barrel, a stem, a donut, or the like. Specific examples of the sliding mechanical element include the inner ring, outer ring and ball of a rolling bearing, sliding bearing, crank shaft, piston, bore and the like.

  On the other hand, a shape having discrete symmetry is a shape in which symmetry is maintained discretely when the shape is rotated 360 ° with respect to a certain axis (see FIG. 1B). ). For example, a square has discrete rotational symmetry because it has a rotational angle that is four-fold symmetric at 360 ° (four-fold symmetry). A specific sliding mechanical element is a gear or the like. As for one-fold symmetry, all shapes are applicable, so it is excluded from the range of discrete rotationally symmetrical shapes.

<Center angle>
In the embodiment of the present invention, the sliding surface may have a shape in which a rotationally symmetric shape is cut out (see FIG. 1 (C)). The angle formed by both ends of the arc of the sliding surface and the radius is defined as a "central angle" and used as an index indicating the amount of notch. When the central angle is different in the rotational symmetry axis direction (the notch amount is different), the maximum central angle is indicated. When the sliding surface is discretely present, as in the case of the inner ring and rolling elements in a rolling bearing, it refers to the angle between the ends of the smallest arc encompassing all the sliding surfaces and the radius. The maximum value of the central angle is 360 °.

<Inside and outside of sliding surface>
When the inside and the outside are described with respect to the sliding surface of the above-mentioned rotationally symmetrical shape, the inside means the side with the rotation symmetry axis, and the outside means the opposite side across the sliding surface ( 1 (A) to (C)).

<Transparent rotational symmetric sliding body and mating sliding body>
The embodiment of the present invention relates to a sliding device for visualizing a sliding interface, and a material which transmits light is used as a material of at least one sliding surface. Moreover, this sliding surface shape is a rotationally symmetrical shape. This sliding body is described as "transparent rotationally symmetric sliding body" and corresponds to the first sliding body. Further, a sliding body which is a sliding counterpart of the transparent sliding body is referred to as a "counter sliding body" and corresponds to a second sliding body.

<Sliding surface and sliding interface>
"Sliding surface" means a surface subjected to sliding, which is defined for one object. On the other hand, "sliding interface" refers to a set of two or more sliding surfaces that exert forces by relative movement, and is defined for two or more objects.

<Light emitted from sliding surface>
When expressing "radiation" as "light emitted from the sliding surface", both the case where the sliding surface (and the lubricant) emits light by itself and the case where the sliding surface reflects the irradiated light Means

<Problems of prior art>
In the prior art, as described above, there is a first problem that light emitted from the sliding surface of the mating sliding body located outside the sliding surface of the transparent rotationally symmetric sliding body can not be detected. In addition, when light emitted from the sliding surface of the mating sliding body located outside the sliding surface of the transparent rotationally symmetric sliding body is detected, noise is generated because the light passes through two or more sliding interfaces. There is a problem.

  A third problem is that, with the device configuration of Patent Document 1, only a part in the circumferential direction can be observed on the sliding bearing sliding surface. Since the coefficient of friction obtained from the sliding device is the response of the entire sliding surface, when only part of the sliding surface can be visualized, one-to-one correspondence between the visualization result and the friction result can not be made, and the usefulness of visualization decreases Do.

  Moreover, in the non-patent documents 1 and 2 described above, as in the patent document 1, only a part in the circumferential direction can be observed on the sliding surface of the rotationally symmetric shape. In the case of this device configuration, it is possible to observe the entire circumference by moving the camera in the circumferential direction and scanning (scanning) the sliding surface. However, scanning generally requires a certain amount of time. Since the condition of the sliding surface changes from moment to moment, it is desirable to be able to observe the entire circumference with one shot. In addition, in order to obtain an observation image of the entire circumference, a hardware mechanism for precisely moving the light detector in the circumferential direction needs to be added, and image processing etc. for connecting detection results is required, which is not simple.

  Thus, in Patent Document 1 and Non-patent Documents 1 and 2, light emitted from the sliding surface of the mating sliding body located outside the rotationally symmetric sliding surface is detected over the entire circumference (360 °) in the circumferential direction. If it can not be detected in one shot. This is because, for visualization, a general light reflector (mirror) or a lens having a light reflection function for condensing light emitted from a plane is used.

<Outline of this embodiment>
Embodiments of the present invention solve the problems of the prior art. First, an outline of the principle for solving the first and second problems will be described. In the embodiment of the present invention, in order to visualize the outer sliding surface, the rotationally symmetrical sliding surface of the inner sliding body is made of a transparent body. Then, inside the transparent sliding surface, a reflector (mirror) or a lens having a reflection function is inserted, which is smaller in size and less in space, as compared with the light detector. As a result, the light emitted from the other sliding body is reflected, guided to a position having a space, and detected by the light detector. Thereby, even if the space is limited, light emitted from the sliding surface of the mating sliding body located outside the sliding surface of the transparent rotationally symmetric sliding body does not pass through two or more sliding interfaces. It becomes detectable by the light detector.

  Next, an outline of the principle for solving the third problem is described. In the embodiment of the present invention, the light having a reflector (mirror) or a lens with a reflection function is captured in order to capture light emitted from the other sliding body and transmitted through the rotationally symmetric sliding surface in one shot all around the circumferential direction. The reflective surface shape of is made rotationally symmetric. As a result, the light emitted from the entire circumferential direction can be reflected, and can be detected by the light detector as described in the solutions of the first and second problems. Here, even when the sliding surface of the mating sliding body is not rotationally symmetrical or when the sliding surface is discretely present, the position (spatial distribution) of the sliding interface is the sliding of the transparent rotational symmetric sliding body It depends on the surface. That is, since the light is distributed on the rotationally symmetric surface, the light radiated from the entire surface of the sliding interface can be detected by making the reflective surface shape of the reflector (mirror) or the lens having the reflection function into the rotationally symmetric shape. become.

  Here, a range in which the embodiment of the present invention is more effective will be described. The embodiment of the present invention solves the first to third problems unique to the case of detecting the light emitted from the mating sliding body located outside the sliding surface of the rotationally symmetric shape. Here, with regard to the first problem and the second problem, as the diameter of the rotationally symmetric shape increases, the space inside the sliding surface also increases, so a reflector (mirror) or reflection as in the embodiment of the present invention Even without using a functional lens, it is possible to directly detect the light by installing the lens and the photodetector inside. In consideration of the size of a general camera, lens and fixing mechanism thereof, a space having a radius larger than 250 mm inside the sliding surface can be sufficiently installed. On the other hand, if the space inside the sliding surface has a radius of 100 mm or less, the installation becomes difficult even if a small camera is selected among general cameras, lenses and their fixing mechanisms. That is, according to the embodiment of the present invention, when the sliding surface is viewed in a cross section orthogonal to the rotational symmetry axis of the sliding surface, the effect is large when the maximum radius in all cross sections is 250 mm or less, and the maximum radius is 100 mm or less Particularly effective in the case of

  In the third problem as well, when the amount of notch on the rotationally symmetric sliding surface is large (the central angle is small), it becomes possible to shoot in one shot even when using a general lens and a camera. If the central angle is less than 10 °, imaging is sufficiently possible. On the other hand, when the angle is 30 ° or more, it is difficult to take one shot with a general lens and camera. That is, according to the embodiment of the present invention, when the sliding surface is viewed in a cross section orthogonal to the rotational symmetry axis of the sliding surface, the effect is large when the maximum central angle in all the cross sections is 10 ° or more. Particularly effective when the angle is 30 ° or more.

<System configuration>
A sliding surface visualization system 10 according to an embodiment of the present invention will be described based on FIGS. 2 to 7.

  In the present embodiment, the case of visualizing a crankshaft journal surface and a sliding surface of a slide bearing in an automobile engine will be described as an example.

  As shown in FIG. 2, the sliding surface visualization system 10 includes an optical system 20 and a sliding system 40.

  The sliding system 40 includes a transparent rotationally symmetrical sliding body 42, a mating sliding body 44, and a sliding mechanism 46. The transparent rotationally symmetric sliding body 42 is, for example, a crankshaft, and the material is sapphire which is a transparent material, and is hollow for inserting a lens.

  The mating slide body 44 is, for example, a slide bearing made of aluminum.

  The sliding mechanism 46 includes a motor 48, a coupling 50, a holding jig 52 for the mating sliding body 44, and a linear guide 54. Thus, a rotary sliding sliding mechanism is realized by the journal surface of the crankshaft which is the transparent rotationally symmetrical sliding body 42 and the slide bearing which is the mating sliding body 44. Further, the holding jig 52 of the mating sliding body 44 is movable by the linear guide 54, and a load is applied by a load mechanism (not shown).

  The optical system 20 includes a lens 22 having a reflection function and a light detector 24, and is attached to the optical stage 21. The lens 22 having a reflecting function is, for example, a rotationally symmetric lens having a convex aspheric reflecting surface and a toric refracting surface, and is emitted from the sliding surface of the sliding bearing which is the mating sliding body 44 and is transparently rotationally symmetric. The light transmitted through the transparent crank shaft as the moving body 42 is reflected by the convex aspheric reflecting surface.

  The light detector 24 is, for example, a digital color camera. The sliding surface of the transparent rotationally symmetrical sliding member 42, which is an inner sliding member, is made of a transparent body, and the lens 22 having a reflection function is introduced inside the sliding surface, and the light emitted from the sliding surface of the mating sliding member 44 The light is detected by the light detector 24 without transmitting light at two or more places on the sliding interface.

<Transparent rotational symmetric sliding body 42>
FIG. 3 shows the shape of a crankshaft which is the transparent rotationally symmetric sliding body 42. As shown in FIG. For example, the outer diameter of the shaft is 48 48 mm, the inner diameter is 34 34 mm (wall thickness 7 mm), and the length is 245 mm. The hatched portion in FIG. 3 is a sliding surface in contact with the bearing of the mating sliding body 44, and has a rotationally symmetrical shape (cylindrical shape). The hole for introducing the lens 22 is not a through hole but a counterbore with a depth of 132 mm. This is for suppressing the strength reduction by hole processing.

  The material of the axis is single crystal sapphire. The reason for using single crystal sapphire instead of general quartz glass as the material of the transparent body is the following two points.

  First, they are stronger than quartz glass and can be tested at higher loads. Secondly, it is because the medium infrared rays to be measured when the temperature measurement by thermography is performed (the quartz glass does not transmit the medium infrared rays).

  The plane orientation of the single crystal was set such that the C axis was in the longitudinal direction of the axis. This is to suppress circumferential variations in various physical properties (such as the thermal expansion coefficient).

  Although the sapphire axis is not coated in this embodiment, an anti-reflection coating may be applied to the inner surface of the axis in order to suppress reflection at the inner surface of the shaft and the air, which causes noise. In the case of oil film measurement by light interference method, the outer surface of the shaft may be provided with an antireflective coating (such as a Cr film) or a protective coating (such as a SiO2 film).

<Sliding body 44>
FIG. 4 shows the shape of the sliding bearing (half) which is the mating sliding body 44. An aluminum alloy slide bearing was used for the slide bearing. For example, the inner diameter is 48 48 mm and the width is 15 mm. The sliding surface has a surface texture called microgrooves. At the time of visualization observation, two half slide bearings shown in FIG. 4 are combined and used in a cylindrical shape. Therefore, the central angle of the sliding interface composed of the shaft sliding surface and the sliding bearing sliding surface is 360 °. Since the field of view of the lens 22 used in this example is 8 mm, the field of view at the time of observation was set from the bearing end to the center as shown in FIG.

<Optical system 20>
The optical system 20 further includes a light source 26, a light guide 28, a beam splitter 30, and a camera lens 32 (see FIG. 5).

  As a lens 22 having a reflection function, a rotationally symmetrical lens (hereinafter, toric lens) having a convex aspheric reflection surface and a toric refractive surface is used. The toric lens is a lens that condenses light from the entire surface of the inner circumferential surface of the cylinder and reflects it in the direction of the cylinder axis. FIG. 6 shows the optical path near the sliding interface by the toric lens. The light collected and reflected by the toric lens is further collected using the camera lens 32, and is imaged on the image pickup element of the digital color camera which is the light detector 24. The field of view in the bearing width direction of the lens 22 was set to 8 mm. Although the lens 22 is not coated in this embodiment, an anti-reflection coating may be applied to the toric refracting surface of the toric lens in order to suppress the reflection of light at the lens 22-air interface which becomes noise.

  Although a toric lens is used in this embodiment, a rotationally symmetric reflector (mirror) or a lens having a rotationally symmetric reflective surface may be used. An example of such a reflector (mirror) is an omnidirectional mirror used in an omnidirectional sensor (see Non-Patent Document 3).

  [Non-patent literature 3]: Viston omnidirectional sensor catalog, [August 3, 2016 search] Internet <URL: http://www.vstone.co.jp/products/sensor_camera/download/omni.pdf>

  As a digital color camera, a 3-CCD digital color camera (AT200-CL manufactured by JAI) is used. The light source 26 is, for example, a xenon flash lamp (L7684 manufactured by Hamamatsu Photonics K.K.), and uses intermittent light from the xenon flash lamp. The half width of the light emission time is 1.75 μs to 2.90 μs as shown in FIG. 7, and light is emitted in synchronization with the shutter timing of the camera. The reason for using the intermittent light with such a short light emission time is to shorten the exposure time, so as to photograph an object with time fluctuation on the sliding surface without flowing.

  With such an optical system 20, light emitted from the light source 26 is incident on the light guide 28, reflected by the beam splitter 30, incident on the hollow portion of the transparent rotationally symmetric sliding body 42, and The reflected light is incident on the entire surface of the sliding interface constituted by the sliding surface of the transparent rotationally symmetric sliding member 42 having a rotationally symmetric shape and the sliding surface of the mating sliding member 44 located outside the same. .

  Then, the light reflected from the entire surface of the sliding interface constituted by the sliding surface of the transparent rotationally symmetric sliding member 42 and the sliding surface of the mating sliding member 44 located on the outside thereof is the lens 22 by the lens 22. The light is reflected, transmitted through the beam splitter 30, and incident on the light detector 24. Thus, the light detector 24 can detect the light without passing through two or more surfaces of the sliding interface.

<Operation of Sliding Surface Visualization System 10>
Next, the operation of the sliding surface visualization system 10 according to the present embodiment will be described.

  First, by driving the motor 48 of the sliding mechanism 46, the transparent rotationally symmetrical sliding body 42 rotates, and the transparent rotationally symmetrical sliding body 42 and the mating sliding body 44 slide against each other while receiving a load, and the sliding interface The light from the light source 25 is incident on the light guide 28, is reflected by the beam splitter 30, and is incident on the hollow portion of the transparent rotationally symmetric sliding body 42. The light incident on the hollow portion of the transparent rotationally symmetric sliding body 42 is reflected by the convex aspheric reflecting surface of the lens 22, and the sliding surface of the transparent rotationally symmetric sliding body 42, which is rotationally symmetric, and the partner located outside thereof. The light is incident on the entire circumference of the sliding interface formed by the sliding surface of the sliding body 44. Then, the light reflected over the entire circumference of the sliding interface is reflected by the convex aspheric reflecting surface of the lens 22, passes through the beam splitter 30, and is incident on the light detector 24. An image captured by the digital color camera which is the light detector 24 is obtained.

<Example>
FIG. 8 shows an optical image of the sliding interface of the transparent simulated crankshaft-slide bearing, which is photographed by the digital color camera which is the light detector 24 in the sliding surface visualization system 10 described in the above embodiment. The cylinder shown in the image is the sliding interface (field width 8 mm). When this toric lens is used, it is possible to obtain a donut-shaped image taken by a camera from above by cutting and opening a slide bearing which is originally a cylinder of the same diameter so as to increase the diameter on the front side. The main imaging is an image obtained by one shooting (one shot), and image processing by software and the like are not performed. The circumferential direction of the donut in FIG. 8 is the circumferential direction of the slide bearing, and the thickness direction of the donut is the width direction of the slide bearing. The outer peripheral side of the donut is the front side (camera side) of the bearing, and the inner peripheral side is the rear side (base side).

  Focusing on the quality of the image, the micro groove texture (concentric streaks) present on the slide bearing surface and the mating surface of the bearing are clearly captured, and it is understood that the quality is sufficient for observation and measurement. . The bright concentric circles observed at the center in the thickness direction of the doughnut are not from the sliding interface but from reflected light from a part of the toric refracting surface. The concentric circles, which become noise in observation, can be suppressed by applying the anti-reflection coating to the toric refracting surface described above.

  As described above, according to the sliding surface visualization system according to the embodiment of the present invention, the sliding surface of the transparent rotationally symmetrical sliding member and the sliding surface of the opposing sliding member on the outside thereof. Since the light emitted from the moving interface can be detected by the photodetector without passing through two or more sliding interfaces, noise can be suppressed, and it can be detected between the transparent sliding symmetrical sliding member and the mating sliding body outside. The sliding surface of can be visualized.

  In addition, the shape of the light reflection surface of the lens provided with the light reflection function is formed so as to reflect the light transmitted through the transparent rotationally symmetric slide body toward the light detector by being emitted from the entire circumference of the slide surface. Because of this shape, the entire circumferential direction (360 °) of the sliding surface can be detected by the photodetector in one shot.

  In the above embodiment, the sliding mechanism realizes the rotational sliding mechanism as an example, but the present invention is not limited to this. For example, as shown in FIG. 9, the sliding mechanism 246 includes a motor 48, a coupling 50, a holding jig 52 for the other sliding body, a linear guide 54, and a ball screw 250, and the motor 48 performs forward rotation. -The reciprocation sliding sliding mechanism which reciprocates may be realized by repeating reversal.

  In addition, although the case where the sliding surface shape and the light reflecting body (mirror) or the reflecting surface of the lens having the light reflecting function have a rotationally symmetric shape has been described, the present invention is not limited thereto. The light reflecting body (mirror) or the reflecting surface of the lens having a light reflecting function may have a shape in which a part of the rotationally symmetrical shape is cut out. In addition, the shape of the sliding surface may be a shape in which a part of a cylindrical shape is cut out. In addition, the light reflecting surface of the lens having the light reflecting function may have a shape in which a part of the convex aspheric surface is cut out.

  In addition, although the case where one transparent rotationally symmetric sliding body and one opposing sliding body slide in a non-lubricated case has been described as an example, the present invention is not limited thereto. Agents may be present. In addition, three or more sliding members may be present.

  Further, although the light detected by the light detector is only the light emitted from the sliding surface of the other sliding body, the light is not limited to this, and the light detected by the light detector is not limited to this. Light emitted from the lubricant (reflected light by the lubricant or fluorescence of the lubricant itself) or light emitted from the sliding surface of the transparent rotationally symmetric sliding body (on the sliding surface of the transparent rotationally symmetric sliding body) Reflected light by the formed reflecting film may be included.

  Also, although the case where the wavelength of light to be handled is visible light is described as an example, the present invention is not limited to this, and materials that transmit or reflect light of wavelengths other than visible light (ultraviolet light, infrared light etc.), detection In the case where there is a detector, the wavelength of light to be handled may be a wavelength (ultraviolet light, infrared light, etc.) other than visible light.

  Further, although the case where the transparent rotationally symmetric sliding body has a hollow portion has been described as an example, the present invention is not limited to this, and the hollow portion may not be provided. In this case, the light reflected by the light reflection body (mirror) or the reflection surface of the lens having a light reflection function is transmitted through the transparent rotationally symmetric sliding body and detected by the light detector.

  In addition, when light reflected by a light reflector (mirror) or a reflection surface of a lens having a light reflection function passes through the hollow portion of the transparent rotationally symmetrical sliding member along the axial direction and is detected by the light detector The light reflected by the light reflecting member (mirror) or the reflecting surface of the lens having a light reflecting function passes in the direction inclined from the axial direction of the transparent rotational symmetrical sliding member, and the transparent rotational symmetrical sliding member The part which is not the hollow part of the moving body may be transmitted and detected by the light detector.

DESCRIPTION OF SYMBOLS 10 Sliding surface visualization system 20 Optical system 21 Optical stage 22 Lens 24 Optical detector 25 Light source 26 Light source 28 Light guide 30 Beam splitter 32 Camera lens 40 Sliding system 42 Transparent rotation symmetrical sliding body 44 Opposite sliding body 46 Sliding mechanism 48 Motor 50 Coupling 52 Holding jig 54 Linear guide 246 Sliding mechanism 250 Ball screw

Claims (11)

A sliding device comprising a first sliding body, a second sliding body, a light reflector, or a lens having a light reflecting function, and a light detector,
The first sliding body and the second sliding body slide against each other to form a sliding interface,
The sliding surface of the first sliding body with the second sliding body is made of a material that transmits light,
The shape of the sliding surface of the first sliding body with the second sliding body is a rotationally symmetrical shape or a shape obtained by cutting a part of the rotationally symmetrical shape,
The sliding surface of the second sliding body exists outside the sliding surface of the first sliding body with the second sliding body,
The light reflector or the lens having the light reflection function is present inside the sliding surface of the first sliding member with the second sliding member,
The light emitted from the sliding surface of the second sliding body with the first sliding body and transmitted through the sliding surface of the first sliding body with the second sliding body is the light reflector or the light. It is reflected by a lens with a reflection function,
The light detector detects the reflected light;
The light emitted from the sliding surface of the second sliding body with the first sliding body does not pass through two or more sliding interfaces in the optical path until it is detected by the light detector Characterized sliding device.   The rotationally symmetric shape of the sliding surface of the first sliding body with the second sliding body has the largest radius in all the cross sections when the sliding surface is viewed in a cross section orthogonal to the rotation axis of the rotationally symmetric shape. The sliding device according to claim 1, characterized in that it is 250 mm or less.   The rotationally symmetric shape of the sliding surface of the first sliding body with the second sliding body has the largest radius in all the cross sections when the sliding surface is viewed in a cross section orthogonal to the rotation axis of the rotationally symmetric shape. The sliding device according to claim 2, characterized in that it is 100 mm or less.   The rotationally symmetrical shape of the sliding surface of the first sliding body with the second sliding body is the maximum central angle in all the cross sections when the rotationally symmetrical shape is viewed in a cross section orthogonal to the rotation axis of the rotationally symmetrical shape. The sliding device according to any one of claims 1 to 3, wherein is 10 degrees or more.   The rotationally symmetrical shape of the sliding surface of the first sliding body with the second sliding body is the maximum central angle in all the cross sections when the rotationally symmetrical shape is viewed in a cross section orthogonal to the rotation axis of the rotationally symmetrical shape. The sliding device according to claim 4, wherein is 30 degrees or more.   The shape of the sliding surface of the first sliding body with the second sliding body is a continuous rotational symmetric shape or a shape obtained by cutting out a part of the continuous rotational symmetric shape. A sliding device according to any one of the preceding claims.   The shape of the light reflection surface of the light reflector or the shape of the light reflection surface of the lens having the light reflection function is emitted from the sliding surface of the second sliding member with the first sliding member, It is characterized in that the light transmitted through the sliding surface of the first sliding member with the second sliding member is formed to be reflected toward the light detector over the entire sliding surface. The sliding device according to any one of claims 1 to 6.   The shape of the light reflecting surface of the light reflector or the shape of the light reflecting surface of the lens having the light reflecting function is a rotationally symmetrical shape or a shape obtained by cutting out a part of the rotationally symmetrical shape. The sliding device according to claim 7.   The shape of the sliding surface of the first sliding body with the second sliding body is a cylindrical shape or a shape obtained by cutting out a part of the cylindrical shape. The sliding device according to any one of the preceding claims.   The sliding device according to any one of claims 1 to 9, wherein the lens having the light reflecting function has a toric refractive surface.   The sliding device according to claim 10, wherein a light reflecting surface of the lens having the light reflecting function has a convex aspheric shape or a shape obtained by cutting out a part of the convex aspheric shape.