JP2010014650A - Apparatus and system for inspecting liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably and accurately measure the degree of degradation of liquids such as lubricating oil for engines. <P>SOLUTION: A degradation diagnostic apparatus includes a rod-like light guide member 50, a light-emitting element 41 arranged at one end of the light guide member 50 for emitting inspection light, and a light-receiving element 42 arranged at the other end of the light guide member 50 for receiving inspection light transmitted through the light guide member 50 while totally reflecting it at an interface of the light guide member 50. Part of the light guide member 50 is coated with a member 51 which forms a non-measuring part, and an uncoated region forms a measuring part 50a. When the inspection light transmits through the measuring part 50a, the energy of the inspection light is reduced by the degree of degradation of oil to be inspected at the interface between the light guide member 50 and oil to be inspected. Changes in the intensity of the inspection light are measured. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid inspection apparatus and inspection system for measuring physical properties of various liquids, and more particularly to a liquid inspection apparatus and inspection system suitable for determining the degree of deterioration or remaining life of a lubricating oil.

  For example, in an engine such as a gas engine for cogeneration (CGS), a gasoline engine, or a diesel engine, lubricating oil is used for friction reduction, cooling, or the like. This lubricating oil deteriorates with use, and causes corrosion and wear of the piston ring and cam, a decrease in lubrication performance, an increase in fuel consumption rate, and further engine troubles. Therefore, it is necessary to replace the lubricating oil in a timely manner. The deterioration of the lubricating oil generally progresses as the operating time becomes longer, but the degree of progress of deterioration differs depending on the use conditions of the engine. For example, when the frequency of high load operation is high or when poor fuel is used, the lubricating oil deteriorates relatively quickly. Therefore, it has been conventionally performed to determine the degree of deterioration of the lubricating oil using an oil deterioration sensor and determine the replacement time of the lubricating oil.

  By the way, in a stationary engine that is installed at a fixed location, such as a gas engine for CGS, a maintenance company goes to the installation location to perform oil sampling, analyze this, and then replace the oil as necessary. ing. Alternatively, the oil change may be performed based on a predetermined operation time or number of days regardless of the degree of deterioration. However, in the former case, local oil sampling work is burdened to judge the degree of deterioration of the lubricating oil, and in the latter case, the oil may be changed when the lubricating oil has not reached the end of its life. There is a bug.

  Therefore, there is a need for a deterioration diagnosis device that can attach a sensor for determining the degree of deterioration of lubricating oil to a gas engine or the like and can accurately determine the oil replacement timing remotely.

  As a conventional oil deterioration sensor, for example, as disclosed in Patent Document 1, a pair of glass rods are immersed in lubricating oil in a state of being opposed to each other with a gap between them, and inspection light is transmitted through the glass rods. It is known to irradiate lubricating oil and detect its transmitted light, and perform deterioration determination based on absorbance or transmitted light amount.

As another conventional oil deterioration sensor, a sensor using the total reflection measurement method (ATR method) is also known as disclosed in Patent Document 2, for example. In the oil deterioration sensor described in Patent Document 2, an optical fiber is provided at one end of a glass rod, and a mirror is provided at the other end. The optical fiber is bifurcated, and a light emitting unit and a light receiving unit are received at each branch end. Each of which is provided. And if a part of the glass rod is immersed in lubricating oil and the inspection light emitted from the light emitting part is incident on the glass rod through the optical fiber, it reflects inside the glass rod. However, the electromagnetic field (evanescent wave) of the propagating light is absorbed according to the degree of contamination of the oil around the glass rod. As a result, the output value of the light receiving unit in the oil deterioration sensor of Patent Document 2 corresponds to the degree of contamination of the lubricating oil, and the degree of deterioration of the lubricating oil can be determined.
JP-A-6-281575 Japanese Patent Laid-Open No. 3-111741

  However, in the oil deterioration sensor described in Patent Document 1, contaminants in the lubricating oil adhere to the end surfaces of a pair of glass rods arranged facing each other with a gap due to long-term use. This causes a problem that it is impossible to determine the degree of deterioration.

  In other words, deterioration due to the use of lubricating oil can be attributed to deterioration of the physical properties of the lubricating oil itself (oxidation, nitration, condensation polymerization, etc. due to heat) and deterioration due to contamination of the lubricating oil. Various pollutants such as combustion products (ultrafine carbon, etc.) and wear metal particles increase, and the lubricating oil becomes polluted.

  In the oil deterioration sensor described in Patent Document 1, the lubricating oil is allowed to pass through a gap between a pair of opposed glass rods. If the gap is too wide, the inspection light is blocked by contaminants in the lubricating oil. Occurrence of a phenomenon (that is, a scattering phenomenon caused by the inspection light hitting a contaminant) becomes excessive, and the amount of light reaching the light receiving element is excessively reduced, making measurement difficult. Therefore, the gap needs to be formed to be several millimeters or less, and the flow of oil through the narrow gap is never good. Therefore, if the contaminant in the lubricating oil increases, the contaminant easily adheres to the end face of the glass rod that forms the gap. If contaminants adhere to the end face of the glass rod, accurate measurement is no longer possible, and the measurement may be impossible due to clogging of the gap.

  In the oil deterioration sensor described in Patent Document 2, measurement is performed in a state where a part of the glass rod is immersed in the lubricating oil. However, the oil level (the position of the upper surface of the lubricating oil) depends on the engine shake or inclination. If it fluctuates, the measurement area (immersion area of the glass rod) also fluctuates, which causes a problem that accurate measurement is difficult.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid inspection apparatus and inspection system capable of stable and accurate measurement.

  A liquid inspection apparatus according to claim 1 of the present invention is a rod-shaped light guide member, a light emitting element that is disposed at one end of the light guide member, emits inspection light, and is disposed at the other end of the light guide member, A light receiving element that receives the inspection light that has propagated through the light guide member while being reflected at the interface of the light guide member, covers a part of the light guide member, and a liquid to be inspected is applied to the light guide member. A non-measuring part forming member that forms a non-measuring part that does not contact, and the measuring part of the light guide member that is not covered by the non-measuring part forming member is disposed in a casing filled with the liquid to be inspected It is characterized by being.

  According to this configuration, a part of the rod-shaped light guide member is covered with the non-measurement portion forming member, and the covered portion becomes a non-measurement portion that is not in contact with the liquid to be inspected and is not covered. The part (the part where the surface of the light guide member is exposed) serves as a measurement part. And at least the measurement part of the light guide member is arranged in a casing filled with the liquid to be inspected, and the liquid to be inspected is in direct contact with the measurement part of the light guide member. In addition, a light emitting element is disposed at one end of the light guide member, and a light receiving element is disposed at the other end, and the inspection light from the light emitting element passes through the light guide member while being reflected at the interface of the light guide member. Propagated and received by the light receiving element.

  Here, in the measurement part of the light guide member, the inspection light penetrates a little toward the liquid to be inspected and is reflected at the interface between the light guide member and the liquid to be inspected. The electromagnetic waves penetrating the liquid to be inspected are so-called evanescent waves. The evanescent wave is absorbed depending on the degree of deterioration of the liquid to be inspected. Therefore, the energy of the inspection light decreases as a result according to the intensity of the absorption. By receiving and measuring this inspection light with a light receiving element, it is possible to determine the degree of deterioration or remaining life of the liquid to be inspected.

  And the area of the measurement part of a light guide member can be changed freely by adjusting the covering area | region of the light guide member by a non-measurement part formation member. Therefore, stable and accurate measurement can be performed by optimizing the area of the measurement unit according to the type of liquid to be inspected, the degree of contamination at the time of deterioration, and the like.

  In addition, the measurement part of the light guide member is in a housing filled with the liquid to be inspected, and the contact area between the measurement part of the light guide member and the liquid to be inspected is constant even when fluctuation or tilt occurs. Therefore, stable and accurate measurement is always possible.

  Further, the liquid inspection apparatus of the present invention does not allow the liquid to be inspected to pass through the narrow gap of the glass rod, such as several millimeters or less, as in the oil deterioration sensor described in Patent Document 1, but measures the light guide member. It is the structure which measures the to-be-inspected liquid around a part. Therefore, even when used for a long period of time, contaminants in the liquid to be inspected do not easily adhere to the measurement part of the light guide member, and stable and accurate measurement is always possible.

  The said structure WHEREIN: It is desirable for the space to be formed between the outer peripheral surface of the said light guide member, and the inner peripheral surface of the said non-measurement part formation member (Claim 2). According to this configuration, the non-measurement portion forming member does not directly contact the outer peripheral surface of the light guide member, but a space is formed between the light guide member and the non-measurement portion formation member to become a non-measurement portion. . Compared with the case where a non-measurement part forming member (solid substance) is brought into direct contact with the outer peripheral surface of the light guide member, the space is filled with the air according to claim 3 or another gas / liquid. The adhesion between the member and the non-measuring part can be improved. Therefore, when the inspection light propagates while reflecting the non-measurement part of the light guide member, a stable propagation state can be secured.

  In the above configuration, it is desirable that the space is filled with air to form an air layer. The air layer is suitable as a non-measuring part, and if the non-measuring part is configured as an air layer, manufacturing can be facilitated.

  According to a fourth aspect of the present invention, there is provided a liquid inspection system comprising: a liquid inspection apparatus according to any one of the first to third aspects; and a part of the liquid from an apparatus in which the liquid is stored. A liquid circulation system that extracts the liquid to be inspected and returns the liquid to be inspected to the device through a predetermined circulation path, and the liquid inspection apparatus is provided in the middle of the circulation path.

  According to this system configuration, it is possible to monitor the degree of deterioration of the liquid for a long period of time stably and non-destructively without stopping the operation of the apparatus in operation by applying the liquid inspection apparatus. Therefore, even with a stationary engine such as a gas engine for CGS, it is possible to determine the oil change timing remotely and accurately. As a result, the maintenance burden is reduced, and the oil change frequency is optimized. Accordingly, the amount of waste oil can be reduced.

  According to the liquid inspection apparatus and inspection system according to the present invention, by adjusting the covering region of the light guide member by the non-measurement portion forming member, according to the type of liquid to be inspected and the degree of contamination during deterioration, etc. The area of the measurement part of the light guide member can be set freely, and the measurement of a highly polluted liquid to be inspected is also possible. Moreover, it is difficult for contaminants in the liquid to be inspected to adhere to the measurement part of the light guide member. Therefore, it is possible to provide a liquid inspection apparatus and inspection system capable of performing stable and accurate measurement.

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

  FIG. 2 is a configuration diagram schematically showing an overall configuration of a lubricant deterioration diagnosis apparatus S (liquid inspection system) which is an embodiment of the liquid inspection apparatus according to the present invention. The deterioration diagnosis device S is for monitoring the degree of deterioration of the lubricating oil 11 used in the engine 10 (an example of “an engine that uses lubricating oil”), and includes an oil circulation system 20 (liquid circulation system). ) And a measuring device 30 (liquid inspection device).

  The engine 10 is an internal combustion engine that provides power to a crankshaft or the like, and includes, for example, a CGS gas engine, a gasoline engine, a diesel engine, or the like. The interior of the engine 10 is filled with lubricating oil 11 to enable a smooth operation of the internal combustion engine. The engine 10 includes an oil take-out hole 12 for extracting a part of the lubricating oil 11 as an inspected oil (inspected liquid), and an oil return hole 13 for returning the inspected oil after the inspection to the engine 10. Is provided.

  The oil circulation system 20 extracts a part of the lubricating oil 11 from the oil take-out hole 12 of the engine 10 as the oil to be inspected, and passes the oil to be inspected to the oil return hole 13 of the engine 10 through a circulation path passing through the measuring device 30. It is something to return. The oil circulation system 20 includes a conduit for circulating the oil to be inspected, a pump 21 for forcibly circulating the oil to be inspected, and an on-off valve 22 for circulating or stopping the oil to be inspected.

  The pipeline includes a first pipeline 201 connecting the oil take-out hole 12 and the pump 21, a second pipeline 202 connecting the pump 21 and the on-off valve 22, the on-off valve 22 and the measuring device 30. A third pipe line 203 that connects the two, and a fourth pipe line 204 that connects the measuring instrument 30 and the oil return hole 13. The pipe line composed of the first to fourth pipe lines 201 to 204 with the measuring device 30 interposed therebetween is a sealed pipe system. In addition, the 1st-4th pipe lines 201-204 can be comprised, for example with a resin pipe.

  As a result of such an oil circulation system 20 being attached to the engine 10, during operation of the engine 10, part of the lubricating oil 11 is extracted from the oil extraction hole 12 as inspection oil by the operation of the pump 21. The extracted oil to be inspected is returned to the oil return hole 13 after the degree of deterioration is optically measured via the measuring device 30.

  As will be described later, the measuring device 30 uses the principle of the ATR (Attenuated Total Reflection) method to determine the degree of deterioration of the inspected oil. The measuring device 30 includes a block member 31 (housing) having an oil passage 32 (liquid passage) through which oil to be inspected passes at a predetermined flow rate. The oil passage 32 is a passage that penetrates the block member 31 linearly, and the block member 31 is installed so that the oil passage 32 faces in the vertical direction.

  The block member 31 is installed such that the height position of the inlet portion 32in of the oil passage 32 is on the lower side and the height position of the outlet portion 32out of the oil passage 32 is on the upper side. And the terminal of the 3rd pipe line 203 (upstream side of a pipe line) is connected to the entrance part 32in, and the starting end of the 4th pipe line 204 (downstream side of a pipe line) is connected to the exit part 32out. Such a measuring device 30 is provided with a processing operation unit 70 that performs an operation for determining the degree of deterioration based on the measurement result of the measuring device 30.

  FIG. 3 is an exploded perspective view showing a detailed structure of the measuring instrument 30 (block member 31), and FIG. 4 is a cross-sectional view of the measuring instrument 30 in an assembled state. The measuring device 30 has a structure in which a first sensor pair 40 </ b> A composed of a pair of a first light emitting element 41 and a first light receiving element 42 is assembled to the block member 31 via a light guide member 50.

  The block member 31 is formed of a carbon steel material for mechanical structure (for example, a product equivalent to S30C to S45C defined in JIS G 4051) or the like, and has a long rectangular shape in the vertical direction. In addition to the oil passage 32 described above, the block member 31 includes a cavity 324 formed in the middle of the oil passage 32, a seal groove 326, first and second insertion holes 331 and 332 for inserting the light guide member, and four A fastening hole 34 is provided.

  The cavity 324 is a space for forming a liquid reservoir for temporarily retaining the oil to be inspected, and is a cylindrical through-hole in a direction orthogonal to the extending direction of the oil passage 32 at a substantially central portion of the block member 31. It is formed as. The oil passage 32 includes a first passage 321 that allows the inlet portion 32in to communicate with the lower portion of the cavity 324, and a second passage 322 that allows the upper portion of the cavity 324 to communicate with the outlet portion 32out. Compared with the first passage 321 and the second passage 322, the cavity 324 is a hole having a larger cross-sectional area.

  As shown in FIG. 4, one end of an elbow type pipe joint 232 is screwed into the inlet portion 32 in, and a terminal joint fitting 231 of the third pipe line 203 is screwed into the other end of the pipe joint 232. Yes. Similarly, one end of an elbow type pipe joint 242 is screwed into the outlet portion 32out, and a start end fitting fitting 241 of the fourth pipe line 204 is screwed into the other end of the pipe joint 242. As a result, as shown by the arrows in the figure, an oil circulation path is formed that enters the first passage 321 from the third conduit 203 and reaches the fourth conduit 204 through the cavity 324 and the second passage 322.

  The seal groove 326 shown in FIG. 3 is an annular groove provided around the opening of the cavity 324. As will be described later with reference to FIG. 5, plate members 35 and 36 for sealing are attached to the opening surfaces on both sides of the cavity 324, and this seal groove 326 has an annular seal member (not shown) for ensuring its sealing performance. 2) is a groove for holding the Accordingly, a similar seal groove is provided on the opposite surface (back surface) of FIG.

  The first insertion hole 331 and the second insertion hole 332 are through holes through which the rod-shaped light guide member 50 is inserted into the cavity 324. Specifically, the first insertion hole 331 is a hole extending in the horizontal direction from one side surface of the block member 31 toward the cavity 324, and the second insertion hole 332 is directed from the other side surface of the block member 31 toward the cavity 324. And a hole extending in the horizontal direction. The first insertion hole 331 and the second insertion hole 332 are provided on the same axis.

  The light guide member 50 for the first sensor pair 40A is inserted through the first insertion hole 331 and the second insertion hole 332. As shown in FIG. 1, a part of the outer periphery of the light guide member 50 is covered with a non-measurement part forming member 51. The substantially central portion of the rod-shaped light guide member 50 is not covered with the non-measurement portion forming member 51 and is exposed. The region of the light guide member 50 that is not covered with the non-measurement part forming member 51 (the gap between the non-measurement part formation members 51) becomes the measurement part 50a. The measurement part 50a of the light guide member 50 is in the cavity 324 so that the oil to be inspected is in direct contact with the measurement part 50a.

  The non-measurement part forming member 51 is a cylindrical hollow member, and has an inner peripheral diameter larger than the outer peripheral diameter of the columnar light guide member 50. Therefore, if the light guide member 50 and the non-measurement part forming member 51 are arranged concentrically, a space (air layer 53) is formed between the two members. In the state where the air layer 53 is formed in this way, the end portions of the non-measurement portion forming member 51 are sealed between the light guide member 50 and the non-measurement portion forming member 51 by the sealing material 52 such as epoxy resin. Has been. Thus, the oil to be inspected in the cavity 324 is prevented from entering the air layer 53 in the non-measurement part forming member 51.

  For example, if the outer peripheral diameter of the columnar light guide member 50 is 4 mm, the inner peripheral diameter of the cylindrical non-measurement part forming member 51 can be 5 mm to 6 mm. The diameter dimensions of the light guide member 50 and the non-measuring part forming member 51 are not limited to the above dimensions, and can be appropriately changed according to the liquid to be measured. The shape of the light guide member 50 is not limited to a cylindrical shape, and may be, for example, a prismatic shape. The cross-sectional shape of the light guide member 50 may also be a triangle, trapezoid, parallelogram, or pentagon or more polygon. The shape of the non-measurement part forming member 51 can be set to an appropriate shape according to the shape of the light guide member 50. The length of the rod-shaped light guide member 50 can be about 4 cm, for example, but the length can also be appropriately changed according to the area of the measurement unit 50 a and the size of the cavity 324.

  As the light guide member 50, for example, various glass materials such as quartz glass, Pyrex (registered trademark of Corning), BK7 glass, and the like can be used. However, the refractive index of the light guide member 50 needs to be larger than the refractive index of the liquid to be measured (oil to be inspected). This is because the measuring device 30 of the present embodiment applies the principle of the ATR method, and therefore it is necessary to satisfy the total reflection condition at the interface (contact surface) between the light guide member 50 and the liquid to be measured. It is. In order to satisfy this total reflection condition, the refractive index of the light guide member 50 is made larger than the refractive index of the liquid to be measured, and the incident angle to the interface of the inspection light (infrared ray) is set to the critical angle (refractive index). Must be larger than the smallest incident angle at which total reflection occurs when light enters from a relatively large material to a relatively small material.

  Therefore, when the refractive index of the liquid to be measured is relatively large, a material having a relatively low refractive index, such as quartz glass, may be unsuitable. Therefore, a material suitable for the liquid to be measured is selected as the light guide member 50. To do.

  As the non-measurement part forming member 51, for example, a metal nipple made of brass or the like can be used, but is not limited thereto. As the non-measuring part forming member 51, various metals or synthetic resins having chemical resistance against the liquid to be measured (oil to be inspected) and physical strength capable of forming the air layer 53 are used as the material. be able to.

  A first light emitting element 41 is attached to one end of the light guide member 50, and a first light receiving element 42 is attached to the other end.

  The 1st light emitting element 41 contains semiconductor light emitting element chips, such as LED which emits test | inspection light, For example, the light emission wavelength range is 870 nm-1600 nm. The first light receiving element 42 is made of a silicon photodiode having sensitivity to the emission wavelength.

  As shown in FIG. 1, the inspection light emitted from the first light emitting element 41 is incident on the end surface of the light guide member 50 and propagates through the light guide member 50. Around the light guide member 50, there is an air layer 53 formed by the non-measurement part forming member 51. Since the refractive index of the light guide member 50 is larger than the oil to be inspected, it is naturally larger than the refractive index of air. Further, since the incident angle of the inspection light is larger than the critical angle at the interface between the light guide member 50 and the air layer 53, total reflection occurs at the interface. Thus, the inspection light propagates through the light guide member 50 while being totally reflected at the interface between the light guide member 50 and the air layer 53. At this time, there is almost no energy loss of reflected light at the interface with the air layer 53.

  When the inspection light propagates to the measurement unit 50 a of the light guide member 50, the measurement unit 50 a switches to total reflection at the interface between the measurement target (inspected oil) in the cavity 324 and the light guide member 50. Here, the refractive index of the light guide member 50 is larger than the oil to be inspected. Further, the incident angle of the inspection light is set larger than the critical angle at the interface between the light guide member 50 and the oil to be inspected. Therefore, total reflection occurs at the interface with the oil to be inspected. When this total reflection occurs, the inspection light slightly permeates the reflected oil side and is reflected at the interface. At this time, the electromagnetic waves that permeate the oil to be inspected are so-called evanescent waves. The evanescent wave is absorbed depending on the degree of deterioration of the oil to be inspected, and as a result, the energy of reflected light (reflected inspection light) decreases according to the intensity of the absorption. An absorption spectrum is obtained by measuring the reflected light.

  The inspection light whose energy is reduced in accordance with the degree of deterioration of the oil to be inspected in the measurement unit 50 a is guided while being totally reflected at the interface between the air layer 53 formed by the non-measurement unit forming member 51 and the light guide member 50. It propagates through the member 50 and reaches the first light receiving element 42. The inspection light is received by the first light receiving element 42.

  As shown in FIGS. 3 and 4, the light guide member 50 to which the non-measuring part forming member 51 is attached is held by a seal fastening mechanism. In this embodiment, the seal fastening mechanism includes a holder member 61, a fastening screw 62, and a seal ring 63.

  The holder member 61 has a through hole that is slightly larger than the outer diameter of the non-measurement portion forming member 51, and holds the non-measurement portion forming member 51 in a state of covering the light guide member 50. Further, the holder member 61 has a fixing thread portion on one end side peripheral wall thereof, and the screw thread portions are formed on threaded portions formed on the inner peripheral walls of the first insertion hole 331 and the second insertion hole 332, respectively. The block member 31 is fixed by being screwed.

  An adjustment thread portion is formed on the peripheral wall on the other end side of each holder member 61, and a fastening screw 62 is screwed into the thread portion. The fastening screw 62 is formed with a through hole through which the light guide member 50 to which the non-measurement part forming member 51 is attached is passed. In addition, two seal rings 63 are fitted on the non-measurement portion forming member 51 so as to be positioned between the holder member 61 and the fastening screw 62. The seal ring 63 is formed of an elastic material and is closely attached to the peripheral wall of the non-measurement part forming member 51, and plays a role of keeping the oil passage 32 and the cavity 324 hermetically sealed.

  Here, the flow of the inspection oil will be described. The block member 31 is installed so that the height position of the inlet portion 32in (inlet side) of the oil passage 32 is on the lower side and the height position of the outlet portion 32out (outlet side) is on the upper side. The oil to be inspected extracted from the engine 10 enters the first passage 321 from the third pipe 203 through the inlet portion 32 in and reaches the cavity 324. Then, by sequentially supplying the oil to be inspected, the cavity 324 is filled with the oil to be inspected so that the space is gradually filled from the lower side to the upper side.

  Thereafter, the oil to be inspected flows to the second passage 322 so as to overflow from the cavity 324, enters the fourth pipe 204 through the outlet portion 32 out, and is returned to the engine 10.

  As described above, since the cavity 324 in which the measurement unit 50a of the light guide member 50 exists is buried so that the oil level rises from the lower side to the upper side, the air is embraced. Absent. Therefore, the cavity 324 is reliably filled with the oil to be inspected without any bubbles. Thereby, it will be in the state which to-be-inspected oil contacted reliably to the measurement part 50a of the light guide member 50, and it can measure the deterioration state of to-be-inspected oil exactly.

  FIG. 5 is a side view showing an actual assembly example of the measuring device 30. Here, an example is shown in which a block member 31R for calibration is attached to the block member 31 described above. The calibration block member 31 </ b> R is the same member as the block member 31 except that the oil passage 32 does not exist, and has a cavity 324 ′ that is substantially the same as the cavity 324.

  The block member 31 and the calibration block member 31R are juxtaposed in the horizontal direction, and plate members 35, 36, and 37 are disposed on both sides and in the middle so as to sandwich them. The plate members 35, 36, and 37 are flat plate members made of carbon steel or the like. Fastening bolts 38 are respectively inserted into the four fastening holes 34 of the block member 31 and the calibration block member 31R, and the fastening nuts 39 are fastened to fix them together. It should be noted that the oil passage 32 and the cavity 324 of the block member 31 are hermetically sealed by closing both side surfaces with the plate members 35 and 36.

  The calibration block member 31R includes a second sensor pair 400A having the same configuration as the first sensor pair 40A. The second sensor pair 400A includes a second light emitting element 43 that generates reference light in the same wavelength region as the first light emitting element 41, a second light receiving element 44 that receives the reference light, and the measurement unit within the cavity 324 ′. A light guide member (not shown) having the same measurement area as 50a is included.

  The oil to be inspected is not circulated through the calibration block member 31R, and light projection and reception by the second light emitting element 43 and the second light receiving element 44 are executed in a state where air exists in the cavity 324 '.

  By providing such a calibration block member 31R, the light projection / reception results of the second light emitting element 43 and the second light receiving element 44 can be used as reference data. In particular, since the block member 31 and the calibration block member 31R are integrated in a manner as shown in FIG. 5, they are thermally coupled, and data such as the amount of transmitted light detected by the block member 31 is excluded. The temperature can be corrected and used without being affected by the temperature.

  In the present embodiment, in addition to attaching the calibration block member 31R, measurement is performed by propagating the inspection light to the rod-shaped light guide member 50, so even if the oil to be inspected has high heat. The light emitting element and the light receiving element provided at both ends of the rod-shaped light guide member 50 are configured to be hardly affected by the heat. That is, the measurement unit 50a of the light guide member 50 and the non-measurement unit forming member 51 that covers the light guide member 50 are in contact with the oil to be inspected, and the light emitting element and the light receiving element are arranged at positions separated from them. Therefore, it is not so affected by heat.

  FIG. 6A is a graph showing temperature characteristics of a general light receiving element, and FIG. 6B is a graph showing temperature characteristics of a general light emitting element. As shown in these graphs, the light receiving element tends to increase the output current when the environmental temperature increases, and the light emitting element tends to decrease the light emission output when the environmental temperature increases. Therefore, when the first light emitting element 41 and the first light receiving element 42 are exposed to a high temperature, a true ATR absorption spectrum cannot be measured due to the influence of the temperature, and as a result, viscosity, base number, acid value, insoluble matter, etc. There is a concern that parameters necessary for oil deterioration diagnosis cannot be calculated. However, according to the present embodiment, the influence of temperature is suppressed as much as possible by the above countermeasures, so that an accurate oil deterioration diagnosis can be performed.

  Next, the processing calculation unit 70 will be described. FIG. 7 is a block diagram illustrating a configuration of the processing calculation unit 70. The processing calculation unit 70 includes drivers 711 and 712, I / V (current / voltage) conversion units 721 and 722, an A / D (analog / digital) conversion unit 73, a CPU (Central Processing Unit) 74, a communication unit 75, The display unit 76, a ROM (Read Only Memory) 77, and a RAM (Random Access Memory) 78 are provided.

  The drivers 711 and 712 give the first light emitting element 41 and the second light emitting element 43 provided in the first sensor pair 40A and the second sensor 400A, respectively, from the measurement control unit 743 of the CPU 74 described later at a predetermined sampling period. Drive (emit light) based on the emitted light control signal. As described above, the first light emitting element 41 and the second light emitting element 43 have the same emission wavelength region.

  The I / V conversion units 721 and 722 convert the current signals output from the first light receiving element 42 and the second light receiving element 44 by photoelectrically converting the inspection light into voltage signals. Here, the voltage signal output from the I / V conversion unit 721 is a signal representing a result of energy attenuation of the inspection light emitted from the first light emitting element 41 according to the degree of deterioration of the oil to be inspected. That is, a voltage signal corresponding to the degree of deterioration of the inspected oil is output from the I / V conversion unit 721. On the other hand, the voltage signal output from the I / V conversion unit 722 is a voltage signal in which the reference light emitted from the second light emitting element 43 is only totally reflected from the interface between the light guide member and air.

  The A / D converter 73 acquires voltage signals output from the I / V converters 721 and 722, converts them into digital signals, and outputs them to the CPU 74.

  The CPU 74 controls the operation of each part of the processing calculation unit 70 and is functionally provided with a temperature correction unit 741, a deterioration calculation unit 742, and a measurement control unit 743. The temperature correction unit 741 uses an output signal from the I / V conversion unit 722 corresponding to the calibration block member 31R as a correction voltage, and outputs from the I / V conversion unit 721 according to the degree of deterioration of the oil to be inspected. An operation for correcting the temperature of the output signal in the inspection light wavelength region is performed. That is, the output signal of the I / V conversion unit 721 is corrected with the output signal of the I / V conversion unit 722 using the same wavelength region.

  The deterioration calculation unit 742 determines the degree of deterioration of the inspected oil based on the output signal from the I / V conversion unit 721. Using the principle of Fourier transform infrared spectroscopy (FT-IR), for example, the deterioration calculation unit 742 obtains an absorption spectrum of the oil to be inspected by performing a fast Fourier transform (FFT), and the oil deterioration An increase in substances that are sometimes generated or mixed in, or a decrease in constituent substances of the oil to be inspected is determined. In addition, the deterioration calculation unit 742 performs a calculation for obtaining a parameter related to the degree of deterioration of the inspected oil. Examples of this parameter include viscosity, base number, acid value, insoluble matter and the like.

  The measurement control unit 743 controls measurement operations by the drivers 711 and 712 and the I / V conversion units 721 and 722 in accordance with a predetermined measurement program. Specifically, timing pulses and the like are given to the drivers 711 and 712 and the I / V converters 721 and 722 to cause the first light emitting element 41 and the second light emitting element 43 to emit light at every sampling period and to synchronize with the light emission timing. Thus, photoelectric conversion signals (measurement data) are acquired from the first light receiving element 42 and the second light receiving element 44.

  FIG. 8 is a graph for explaining temperature correction processing in the temperature correction unit 741. The output voltage from the I / V conversion unit 721 decreases as the temperature increases, as indicated by the characteristic indicated by C1. On the other hand, the output voltage from the I / V conversion unit 722 corresponding to the calibration block member 31R also shows the same gradient as the characteristic indicated by reference C2 because the blocks are thermally coupled. Therefore, by compensating the characteristic of the code C1 with the characteristic of the code C2, it is possible to obtain a characteristic having almost no temperature dependence as indicated by the code C3.

  Returning to FIG. 7, the communication unit 75 performs data communication with an external terminal or the like. For example, the deterioration diagnosis result by the deterioration calculation unit 742 is transmitted to a management center or the like that exists in a remote place via the Internet. To do. The display unit 76 includes a liquid crystal display or the like, and displays, for example, a deterioration diagnosis result by the deterioration calculation unit 642 in a predetermined format.

  The ROM 77 stores an operation program of the degradation diagnosis apparatus S and the like. The RAM 78 temporarily stores a data signal given from the A / D converter 73, a deterioration diagnosis result by the deterioration calculator 742, and the like.

  The operation of the lubricant deterioration diagnosis device S according to the present embodiment configured as described above will be described. When the operation of the engine 10 is started, the driving of the pump 21 is also started, and a part of the lubricating oil 11 is extracted from the oil extraction hole 12 as the oil to be inspected. The extracted oil to be inspected is guided to the block member 31 of the measuring device 30 through the first to third pipes 201 to 203 and enters the oil passage 32 from the inlet 32in (see FIG. 2).

  Thereafter, the oil to be inspected passes through the oil passage 32 while filling the space of the cavity 324 (see FIG. 3). At this time, in the cavity 324, the inspection light emitted from the first light emitting element 41 is attenuated in energy in accordance with the degree of deterioration of the oil to be inspected in the measuring unit 50a and received by the first light receiving element 42.

  Here, the area of the measuring part 50a of the light guide member 50 can be freely designed according to the type of oil to be inspected, the degree of contamination during deterioration, and the like. For example, when the light guide member 50 has a cylindrical shape with a diameter of 4 mm, the length of the measurement part 50a (the gap between the non-measurement part forming members 51) can be adjusted to about 1 cm to 2 cm. Usually, the lower the pollution level at the time of deterioration of the oil to be inspected, the smaller the amount of change in the energy attenuation of the inspection light due to the oil deterioration. In other words, adjustment is made so that the amount of change in energy attenuation can be accurately grasped.

  Thereafter, based on the light reception data of the first light receiving element 42, a parameter relating to the degree of deterioration of the oil to be inspected is calculated by the processing calculation unit 70 (see FIG. 7). The calculation result is transmitted to an external terminal or the like through the communication unit 75 or displayed on the display unit 76. On the other hand, the oil to be inspected discharged from the outlet portion 32out of the oil passage 32 is returned to the engine 10 via the oil return hole 13 through the fourth conduit 204. Hereinafter, this operation is continued during the operation period of the engine 10.

  According to the lubrication oil deterioration diagnosis apparatus S described above, the area of the measurement part 50a of the light guide member 50 can be freely changed by adjusting the covering region of the light guide member 50 by the non-measurement part forming member 51. can do. Therefore, stable and accurate measurement can be performed by optimizing the area of the measurement unit 50a in advance according to the type of oil to be inspected, the degree of contamination at the time of deterioration, and the like.

  The measurement unit 50a of the light guide member 50 is in the cavity of the block member 31, and the contact area between the lubricating oil filled in the cavity and the measurement unit 50a is constant even if the engine 10 is shaken or tilted. is doing. Therefore, stable and accurate measurement is always possible.

  Further, the deterioration diagnosis device S of the present embodiment does not allow the lubricating oil to pass through a narrow gap of the glass rod such as several millimeters or less like the oil deterioration sensor described in Patent Document 1, but instead of the light guide member 50. The configuration is such that the oil to be inspected passes around the measurement unit 50a. That is, in the deterioration diagnosis device S of the present embodiment, contaminants in oil are difficult to adhere to the measurement unit 50a of the light guide member 50 even when used for a long period of time, and stable and accurate measurement is possible at all times. .

  Further, the measuring instrument 30 of the degradation diagnosis apparatus S of the present embodiment does not need to use an optical fiber or the like at the joint between the light emitting element and the light guide member 50. Therefore, expensive parts and processing are unnecessary in the joint, and processing is easy and can be manufactured at low cost.

  In addition, according to the deterioration diagnosis device S of the present embodiment, the deterioration degree of the lubricating oil 11 can be monitored stably for a long period of time without stopping the operation of the engine 10 in operation. Therefore, even if it is a stationary engine such as a gas engine for CGS, it is possible to determine the oil change timing remotely and accurately by transmitting the deterioration diagnosis result from the communication unit 75, and as a result The maintenance burden can be reduced, the frequency of oil change can be optimized, and the amount of waste oil associated therewith can be reduced.

  In addition, since the deterioration of the oil to be inspected is measured through the heat insulating light guide member 50 such as a glass rod, even if the oil to be inspected has high heat, the light emitting element and the light receiving element are affected by the heat. Not receive. Further, the block member 31 is installed so that the inlet portion 32in of the oil passage 32 is on the lower side and the outlet portion 32out is on the upper side, so that the oil to be inspected can exit the outlet portion 32out while reliably filling the space of the oil passage 32. Head for. For this reason, air does not get caught in the cavity of the block member 31, and the deterioration state of the to-be-inspected oil can be measured accurately.

  Although various embodiments of the present invention have been described above, the present invention is not limited to this, and can take modified embodiments such as the following [1] to [5].

  [1] In the above embodiment, an example in which only one set of light emitting element and light receiving element is used is shown, but two or more sets of light emitting element and light receiving element having different wavelength regions may be used.

  [2] In the above embodiment, the engine 10 is given as an example of the engine. However, the present invention can be applied to other engines using lubricating oil other than the engine. For example, the present invention can also be applied to deterioration diagnosis of lubricating oil used in compressors, gear devices, and the like.

  [3] In the above embodiment, the deterioration diagnosis of the lubricating oil is exemplified, but the present invention can also be applied to an inspection device that inspects the physical properties of various liquids other than the lubricating oil. For example, the present invention can be applied to inspection uses such as cooling water, industrial water, hot spring water, liquid fuel, and chemicals.

  [4] In the above embodiment, as shown in FIG. 1, two non-measurement part forming members 51 are used, and only one measurement part 50 a of the light guide member 50 is formed in the gap between the non-measurement part formation members 51. Although an example was given, it is not limited to this. That is, it is also possible to use two or more non-measurement part forming members 51, to form two or more of these gaps, and to form two or more measurement parts 50a of the light guide member 50.

  [5] In the above embodiment, an example in which the air layer 53 is formed between the light guide member 50 and the non-measurement portion forming member 51 has been described, but in the space between the light guide member 50 and the non-measurement portion forming member 51. The non-measuring part may be formed by filling a substance other than air, for example, a gas or liquid such as nitrogen. Alternatively, the non-measurement part forming member 51 itself may be brought into close contact with the light guide member 50 to form the non-measurement part (in this case, the sealing material 52 is unnecessary).

  The substance constituting the non-measurement part desirably has a refractive index sufficiently smaller than the refractive index of the light guide member 50 so as to satisfy the total reflection condition at the interface with the light guide member 50. Further, the substance constituting the non-measuring part is preferably a substance that sufficiently absorbs evanescent waves at the interface with the light guide member 50.

  By the way, the space between the light guide member 50 and the non-measurement part forming member 51 is filled with a gas such as air as compared with the case where the non-measurement part formation member 51 (solid substance) is brought into direct contact with the outer peripheral surface of the light guide member 50. Thus, it is preferable to configure the non-measuring part. This is because if the space between the light guide member 50 and the non-measurement portion forming member 51 is filled with gas, the adhesion between the light guide member 50 and the substance forming the non-measurement portion can be improved, and the inspection light This is because when the light propagates through the non-measurement portion of the light guide member 50 while being totally reflected, a stable propagation state can be secured. In particular, the air layer 53 is suitable as a non-measurement part, and if the non-measurement part is configured as an air layer, manufacturing can be facilitated.

It is principal part sectional drawing of the measuring device in the deterioration diagnosis apparatus S of the lubricating oil which concerns on embodiment of this invention. 1 is a configuration diagram schematically showing an overall configuration of a deterioration diagnosis apparatus S. FIG. It is a disassembled perspective view which shows the detailed structure of a measuring device (block member). It is sectional drawing of the measuring device of the assembled state. It is a side view which shows the actual assembly example of a measuring device. (A) is a graph which shows the temperature characteristic of a general light receiving element, (b) is a graph which shows the temperature characteristic of a general light emitting element. It is a block diagram which shows the structure of a process calculating part. It is a graph for demonstrating the temperature correction process in a temperature correction part.

Explanation of symbols

S Lubricating oil deterioration diagnosis device (liquid inspection system)
10 Engine (Equipment; Engine that uses lubricating oil)
11 Lubricating oil 20 Oil circulation system (liquid circulation system)
201-204 1st-4th pipe line 30 Measuring device (liquid inspection apparatus)
31 Block member (housing)
32 Oil passage 32in Inlet part 32out Outlet part 324 Cavities 41, 43 First and second light emitting elements 42, 44 First and second light receiving elements 50 Light guiding member 50a Measuring part 51 Non-measuring part forming member 52 Sealing material 53 Air layer 70 processing operation part

Claims (4)

A rod-shaped light guide member;
A light emitting element that is disposed at one end of the light guide member and emits inspection light;
A light receiving element that is disposed at the other end of the light guide member and receives the inspection light propagated through the light guide member while being reflected at the interface of the light guide member;
A non-measurement part forming member that covers a part of the light guide member and forms a non-measurement part in which the liquid to be inspected does not come into contact with the light guide member;
The liquid inspection apparatus, wherein the measurement part of the light guide member not covered by the non-measurement part forming member is arranged in a casing filled with the liquid to be inspected.   The liquid inspection apparatus according to claim 1, wherein a space is formed between an outer peripheral surface of the light guide member and an inner peripheral surface of the non-measurement portion forming member.   The liquid inspection apparatus according to claim 2, wherein the space is filled with air to form an air layer. A liquid inspection apparatus according to any one of claims 1 to 3,
A liquid circulation system for extracting a part of the liquid from the device in which the liquid is stored as the liquid to be inspected and returning the liquid to be inspected to the device through a predetermined circulation path;
A liquid inspection system, wherein the liquid inspection device is provided in the middle of the circulation path.

Images