Turbidity detection device

Abstract

The present invention aims to provide a turbidity judgment device that is easy to use for judging the turbidity of hydraulic oil. The turbidity judgment device (10) for judging the turbidity of hydraulic oil includes a photographed component (40), a camera unit (35), and a judgment unit (25). The photographed component (40) has bright and dark areas. The camera unit (35) is positioned away from the photographed component (40) so that hydraulic oil exists between the camera unit (35) and the photographed component (40). The camera unit (35) acquires an image of the photographed component (40) as a judgment image. The judgment unit (25) judges the degree of turbidity of the hydraulic oil based on the tone difference between the bright and dark areas in the judgment image.

Description

[Technical Field]

[0001] This disclosure relates to a turbidity judgment device and a turbidity judgment system for judging the degree of turbidity of hydraulic oil. [Previous Technology]

[0002] For example, hydraulic oil is used to operate hydraulic equipment such as hydraulic cylinders mounted on machine tools. Hydraulic oil gradually deteriorates due to the introduction of foreign matter or oxidation. Devices for judging the condition of hydraulic oil are known in the past. Patent Document 1 discloses a device for judging the deterioration of hydraulic oil.

[0003] Patent Document 1: International Publication No. 2015 / 060457 [Summary of the Invention]

[0003] -The technical problem that the invention aims to solve-

[0004] In the past, most devices for judging the state of hydraulic oil required extracting a test sample of hydraulic oil from the hydraulic equipment and placing it in the device, which was inconvenient to operate.

[0005] The purpose of this disclosure is to provide a turbidity judgment device that is easy to use for judging the turbidity of hydraulic oil.

[0005] -Technical means for solving technical problems-

[0006] The first aspect of this disclosure is a turbidity judgment device 10, which judges the turbidity of hydraulic oil in hydraulic equipment. The turbidity judgment device 10 includes a photographed component 40, a camera unit 35, and a judgment unit 25. The photographed component 40 forms a bright part 51 and a dark part 52. The camera unit 35 is located away from the photographed component 40 so that there is hydraulic oil between the camera unit 35 and the photographed component 40. The camera unit 35 acquires an image of the photographed component 40 as a judgment image 50. The judgment unit 25 performs a turbidity judgment operation based on the tone difference between the bright part 51 and the dark part 52 in the judgment image 50 acquired by the camera unit 35 to judge the degree of turbidity of the hydraulic oil.

[0007] In the first state, the camera unit 35 acquires an image of the photographed component 40 as a judgment image 50. Hydraulic oil, which is the object of turbidity judgment, exists between the camera unit 35 and the photographed component 40. The tone difference between the bright areas 51 and the dark areas 52 in the judgment image 50 varies depending on the degree of turbidity of the hydraulic oil present between the camera unit 35 and the photographed component 40. Therefore, the judgment unit 25 judges the degree of turbidity of the hydraulic oil based on the tone difference between the bright areas 51 and the dark areas 52 in the judgment image 50.

[0008] The first-state turbidity determination device 10 can determine the degree of turbidity of hydraulic oil as long as the hydraulic oil to be determined is present between the camera unit 35 and the photographed component 40. Therefore, if the turbidity determination device 10 is used, the degree of turbidity of hydraulic oil can be determined without collecting a test sample of hydraulic oil from the hydraulic equipment.

[0009] The second state of this disclosure is based on the first state of the above. In the above turbidity judgment work, the smaller the tone difference between the bright part 51 and the dark part 52 in the above judgment image 50, the higher the turbidity of the above hydraulic oil is judged by the judgment unit 25.

[0010] As the turbidity of the hydraulic oil increases, the tone difference between the bright part 51 and the dark part 52 in the image 50 decreases. The second-state judgment unit 25 thereby judges the turbidity of the hydraulic oil.

[0011] The third state sample of this disclosure is based on the first or second state sample mentioned above, wherein the aforementioned turbidity judgment work is the work of the aforementioned judgment unit 25 to judge the degree of turbidity of the aforementioned hydraulic oil by comparing the level difference of the aforementioned bright part 51 and the aforementioned dark part 52 in the aforementioned judgment image 50 with the reference level difference.

[0012] In the third state of the invention, the judgment unit 25 judges the degree of turbidity of the hydraulic oil by comparing the level difference between the bright part 51 and the dark part 52 in the judgment image 50 with the reference level difference.

[0013] The fourth state sample of this disclosure is based on the aforementioned third state sample, wherein the aforementioned reference level adjustment is the level adjustment of the aforementioned bright part 51 and the aforementioned dark part 52 in the aforementioned judgment image 50 acquired by the aforementioned camera unit 35 under the condition that there is the aforementioned hydraulic oil in a non-turbid state between the aforementioned photographed component 40 and the aforementioned camera unit 35.

[0014] In the fourth state, the judgment unit 25 uses the level difference between the bright part 51 and the dark part 52 when the hydraulic oil between the photographed part 40 and the camera unit 35 is in a turbid state as the reference level difference.

[0015] The fifth state sample of this disclosure is based on the aforementioned third or fourth state sample, wherein the aforementioned judgment unit 25 performs a color judgment operation on the aforementioned hydraulic oil color based on the aforementioned judgment image 50. In the aforementioned turbidity judgment operation, the aforementioned judgment unit 25 compares the aforementioned reference level adjustment corresponding to the color of the aforementioned hydraulic oil that has been judged in the aforementioned color judgment operation with the aforementioned bright part 51 and the aforementioned dark part 52 level adjustment in the aforementioned judgment image 50.

[0016] The fifth-state judgment unit 25 judges the color of the hydraulic oil during color judgment. During turbidity judgment, the judgment unit 25 compares the reference tone difference corresponding to the color of the hydraulic oil with the tone difference between the bright areas 51 and dark areas 52 in the judgment image 50 acquired by the imaging unit 35. Therefore, even if the color of the hydraulic oil changes during use, the judgment unit 25 can appropriately judge the degree of turbidity of the hydraulic oil.

[0017] The sixth state of this disclosure is based on the fifth state of the above, wherein the portion of the above-mentioned judgment image 50 that includes only the above-mentioned bright part 51 is the first region 56, and the above-mentioned color judgment work is the work of the above-mentioned judgment unit 25 to judge the color of the above-mentioned hydraulic oil based on the above-mentioned first region 56 of the above-mentioned judgment image 50.

[0018] In the sixth state, the judgment unit 25 judges the color of the hydraulic oil based on the first region 56, which contains only a part of the judgment image 50, namely the bright part 51.

[0019] The seventh state of this disclosure is based on any of the first to sixth state of the above, wherein the photographed component 40 forms a plurality of the aforementioned bright parts 51 and a plurality of the aforementioned dark parts 52, and the region in the aforementioned judgment image 50 that includes the plurality of the aforementioned bright parts 51 and the plurality of the aforementioned dark parts 52 is a second region 57. In the aforementioned turbidity judgment work, the aforementioned judgment unit 25 judges the degree of turbidity of the aforementioned hydraulic oil based on the difference between the maximum value of the tone value of the aforementioned bright parts 51 and the minimum value of the tone value of the aforementioned dark parts 52 in the aforementioned second region 57.

[0020] In the seventh state sample, the second region 57 of the judgment image 50 includes a plurality of bright areas 51 and a plurality of dark areas 52. The judgment unit 25 determines the degree of turbidity of the hydraulic oil based on the difference between the "maximum value of the tone value of the bright area 51" and the "minimum value of the tone value of the dark area 52" in the second region 57.

[0021] The eighth state sample of this disclosure is based on any of the first to sixth state samples mentioned above, wherein the aforementioned judgment unit 25 performs the work of judging the cause of the aforementioned hydraulic oil turbidity.

[0022] In the eighth state sample, the judgment unit 25 determines the cause of the hydraulic oil turbidity.

[0023] The ninth state of this disclosure is based on the aforementioned eighth state, wherein the region in the aforementioned judgment image 50 that includes both the aforementioned bright part 51 and the aforementioned dark part 52 is the second region 57, and the aforementioned cause determination work is the work of the aforementioned judgment unit 25 to determine the cause of the aforementioned hydraulic oil turbidity based on the average value of the aforementioned second region 57 of the aforementioned judgment image 50.

[0024] In the ninth state sample, the second region 57 of the judgment image 50 includes both a bright area 51 and a dark area 52. In the cause determination work, the judgment unit 25 determines the cause of hydraulic oil turbidity based on the average tone value of the second region 57.

[0025] The tenth state of this disclosure is based on the aforementioned ninth state, wherein the aforementioned photographed component 40 forms a plurality of the aforementioned bright parts 51 and a plurality of the aforementioned dark parts 52, and the aforementioned second region 57 is the region in the aforementioned judgment image 50 that includes a plurality of the aforementioned bright parts 51 and a plurality of the aforementioned dark parts 52.

[0026] In the tenth state sample, the second region 57 of the image 50 for judgment includes a plurality of bright parts 51 and a plurality of dark parts 52.

[0027] The eleventh state of this disclosure is based on the aforementioned ninth or tenth state, wherein the aforementioned cause determination work is the work of the aforementioned determination unit 25 to determine the cause of the aforementioned hydraulic oil turbidity by comparing the average value of the pitch value of the aforementioned second region 57 of the aforementioned determination image 50 with the reference pitch value.

[0028] In the cause determination work, the eleventh state determination unit 25 determines the cause of hydraulic oil turbidity by comparing the average value of the tone value of the second region 57 of the determination image 50 with the reference tone value.

[0029] The twelfth state sample of this disclosure is based on the aforementioned eleventh state sample, wherein the aforementioned reference tone value is the tone value of the aforementioned bright part 51 in the aforementioned judgment image 50 acquired by the aforementioned camera unit 35 under the condition that there is no turbidity in the aforementioned hydraulic oil between the aforementioned photographed component 40 and the aforementioned camera unit 35.

[0030] In the twelfth state, the determination unit 25 uses the tone value of the bright part 51 when the hydraulic oil between the photographed part 40 and the camera unit 35 is in a non-turbid state as the reference tone value.

[0031] The thirteenth state of this disclosure is based on the eleventh or twelfth state, wherein in the aforementioned cause determination work, when the average value of the pitch value of the second region 57 of the aforementioned determination image 50 is higher than the aforementioned reference pitch value, the aforementioned determination unit 25 determines that the cause of the aforementioned hydraulic oil turbidity is water mixed into the aforementioned hydraulic oil.

[0032] In the cause determination work, when the average value of the tone value of the second region 57 of the image 50 is closer to the tone value of "white" than the reference tone value, the thirteenth state determination unit 25 determines that the cause of the hydraulic oil turbidity is water mixed into the hydraulic oil.

[0033] The fourteenth state of this disclosure is based on any of the eleventh to thirteenth states, wherein in the aforementioned cause determination work, when the average value of the pitch value of the second region of the aforementioned determination image 50 is lower than the aforementioned reference pitch value, the aforementioned determination unit 25 determines that the cause of the aforementioned hydraulic oil turbidity is that solid matter has mixed into the aforementioned hydraulic oil.

[0034] In the cause determination work, when the average value of the tone value of the second region 57 of the determination image 50 is closer to the tone value of "black" than the reference tone value, the determination unit 25 of the fourteenth state determines that the cause of the hydraulic oil turbidity is that solid matter (such as sludge particles) has mixed into the hydraulic oil.

[0035] The fifteenth aspect of this disclosure is based on any of the first to fourteenth aspects, wherein a through hole 43 is formed on the photographed component 40, which opens on the surface opposite to the camera unit 35, the portion of the photographed component 40 other than the through hole 43 forms the bright portion 51, and the through hole 43 forms the dark portion 52.

[0036] A through hole 43 is formed on the photographed component 40 of the fifteenth state. The portion of the photographed component 40 other than the through hole 43 forms a bright part 51 due to reflected light. The through hole 43 of the photographed component 40 forms a dark part 52 because it does not reflect light.

[0037] The sixteenth state of this disclosure is based on the aforementioned fifteenth state, wherein a plurality of the aforementioned through holes 43 are formed on the aforementioned photographed component 40.

[0038] A plurality of through holes 43 are formed on the photographed component 40 in the sixteenth state. Therefore, the photographed component 40 forms a plurality of bright areas 51 and a plurality of dark areas 52.

[0039] The seventeenth state of this disclosure is based on the fifteenth or sixteenth state mentioned above, wherein the photographed component 40 is white.

[0040] In the seventeenth state, the white photographed part 40 forms a bright part 51.

[0041] The eighteenth state of this disclosure is based on any of the first to eighteenth states mentioned above, wherein the photographed component 40 is fixed to the camera unit 35.

[0042] In the eighteenth state, the distance between the photographed part 40 and the camera part 35 remains constant.

[0043] The nineteenth aspect of this disclosure, based on the aforementioned eighteenth aspect, includes a mesh-like partition member 31 that surrounds the space 32 between the aforementioned photographed component 40 and the aforementioned camera unit 35.

[0044] In the nineteenth state, the space 32 between the photographed component 40 and the camera unit 35 is surrounded by the partition member 31. The partition member 31 is mesh-like. Therefore, it is possible to allow hydraulic oil to flow into the space 32 between the photographed component 40 and the camera unit 35, while the partition member 31 can be used to prevent foreign objects from entering the space 32 between the photographed component 40 and the camera unit 35.

[0045] The twentieth aspect of this disclosure, based on the first to fourteenth aspects mentioned above, includes an intermediate component 73, which is arranged between the photographed component 40 and the camera unit 35, and is made of a transparent material. An oil passage 74 for allowing hydraulic oil to flow is formed inside the intermediate component 73.

[0046] In the twentieth state, the intermediate component 73 is disposed between the photographed component 40 and the camera unit 35. With hydraulic oil flowing through the oil passage 74 of the intermediate component 73, there is hydraulic oil between the camera unit 35 and the photographed component 40 that is subject to turbidity assessment. In this state, the camera unit 35 acquires an image of the photographed component 40 as a assessment image 50.

[0047] In the twentieth state, the hydraulic oil, which is the object of turbidity assessment, flows in the oil passage 74 formed inside the intermediate component 73. In this state, the hydraulic oil does not come into contact with the photographed component 40 and the camera unit 35. Therefore, foreign matter contained in the hydraulic oil will not adhere to the photographed component 40 and the camera unit 35.

[0048] The twenty-first embodiment of this disclosure is based on the twentieth embodiment described above, wherein the intermediate component 73 has a first side surface 73a and a second side surface 73b, the first side surface 73a and the second side surface 73b are respectively planes, the first side surface 73a and the second side surface 73b are parallel to each other, in the intermediate component 73, the oil passage 74 is arranged between the first side surface 73a and the second side surface 73b, the photographed component 40 is arranged to contact the first side surface 73a of the intermediate component 73, and the camera unit 35 is arranged at a position opposite to the second side surface 73b of the intermediate component 73.

[0049] In the twenty-first state, the first side 73a of the intermediate member 73 that contacts the photographed member 40 is a plane. The camera unit 35 faces the second side 73b of the intermediate member 73 and acquires an image of the photographed member 40 arranged on the opposite side of the intermediate member 73 as a judgment image 50. The second side 73b of the intermediate member 73 is a plane parallel to the first side 73a. Therefore, the camera unit 35 can acquire an image of the photographed member 40 with less distortion as the judgment image 50.

[0050] The 22nd embodiment of this disclosure is based on the aforementioned 20th or 21st embodiment, and includes a first connector component 75a and a second connector component 75b. The first connector component 75a is connected to one end of the aforementioned oil passage 74 and is connected to the oil pipe 63 for the flow of the aforementioned hydraulic oil. The second connector component 75b is connected to the other end of the aforementioned oil passage 74 and is connected to the aforementioned oil pipe 63.

[0051] In the twenty-second state, the oil passage 74 formed on the intermediate component 73 is connected to the oil pipe 63 via the first connector component 75a and the second connector component 75b. Therefore, the hydraulic oil flowing through the oil pipe 63 will pass through the oil passage 74 of the intermediate component 73.

[0052] The 23rd embodiment of this disclosure is based on any of the 20th to 22nd embodiments mentioned above, and includes a housing 71, which houses the aforementioned photographed component 40, the aforementioned camera unit 35 and the aforementioned intermediate component 73.

[0053] In the twenty-third state, the photographed component 40, the camera unit 35, and the intermediate component 73 are arranged in the housing 71.

[0054] The twenty-fourth aspect of this disclosure is based on the aforementioned twenty-third aspect, and includes a light source 36 housed in the aforementioned housing 71, which is made of an opaque material.

[0055] In the twenty-fourth state, the photographed component 40, the camera unit 35, the intermediate component 73, and the light source 36 are arranged inside the housing 71. The housing 71 is opaque. Inside the housing 71, the camera unit 35 acquires an image of the photographed component 40 illuminated only by the light emitted from the light source 36, as a judgment image 50. Therefore, the camera unit 35 is able to acquire an image of the photographed component 40 without being affected by light outside the housing 71.

[0056] The twenty-fifth embodiment of this disclosure is based on the twenty-fourth embodiment described above, wherein the oil passage 74 of the intermediate component 73 is a straight passage, and the light source 36 includes a first light source 36a and a second light source 36b. The first light source 36a, the camera unit 35 and the second light source 36b are arranged in a row along the extension direction of the oil passage 74.

[0057] In the twenty-fifth embodiment, the imaging unit 35 acquires an image of the photographed component 40 that has received light emitted by the first light source 36a and the second light source 36b, respectively. In this embodiment, the first light source 36a, the imaging unit 35, and the second light source 36b are arranged in a row along a straight oil passage 74. Therefore, the imaging unit 35 is able to acquire an image of the photographed component 40 that has received light of relatively uniform intensity.

[0058] The twenty-sixth aspect of this disclosure is a turbidity judgment system 15, which judges the turbidity of hydraulic oil in a hydraulic device. It includes a photographed component 40, a camera unit 35, and a judgment unit 25. The photographed component 40 forms a bright part 51 and a dark part 52. The camera unit 35 is located away from the photographed component 40 so that there is hydraulic oil between the camera unit 35 and the photographed component 40. The camera unit 35 acquires an image of the photographed component 40 as a judgment image 50. The judgment unit 25 performs a turbidity judgment operation based on the tone difference between the bright part 51 and the dark part 52 in the judgment image 50 acquired by the camera unit 35 to judge the degree of turbidity of the hydraulic oil.

[0059] In the twenty-sixth state, the camera unit 35 acquires an image of the photographed component 40 as a judgment image 50. Hydraulic oil, which is the object of turbidity judgment, exists between the camera unit 35 and the photographed component 40. The tone difference between the bright areas 51 and the dark areas 52 in the judgment image 50 varies depending on the degree of turbidity of the hydraulic oil present between the camera unit 35 and the photographed component 40. Therefore, the judgment unit 25 judges the degree of turbidity of the hydraulic oil based on the tone difference between the bright areas 51 and the dark areas 52 in the judgment image 50.

[0060] The turbidity judgment system 15 of the twenty-sixth state can determine the degree of turbidity of hydraulic oil as long as the hydraulic oil to be judged is present between the camera unit 35 and the photographed component 40. Therefore, if the turbidity judgment device 10 is used, the degree of turbidity of hydraulic oil can be determined without collecting a test sample of hydraulic oil from the hydraulic equipment. [Simplified Explanation of the Diagram]

[0061] Figure 1 is a simplified cross-sectional view of the hydraulic oil tank, which shows the setting state of the turbidity judgment device in the first embodiment.

[0061] Figure 2 is a front view of the turbidity judgment device of the first embodiment.

[0061] Figure 3 is a simplified cross-sectional view of the main part of the turbidity judgment device in the first embodiment.

[0061] Figure 4 is a top view of the photographed component of the turbidity judgment device in the first embodiment.

[0061] Figure 5 is a perspective view of the photographed component of the turbidity judgment device in the first embodiment.

[0061] Figure 6 is a block diagram showing the structure of the judgment section of the turbidity judgment device in the first embodiment.

[0061] Figure 7 is an example of a judgment image acquired by the camera of the turbidity judgment device in the first embodiment.

[0061] Figure 8 shows an example of an image used for judgment, which represents the first region.

[0061] Figure 9 shows an example of an image used for judgment, which represents the second region.

[0061] Figure 10 is a graph showing the tone value of the second region of the image when the hydraulic oil is clear.

[0061] Figure 11 is a diagram showing the level distinction of the baseline level adjustment ΔVC_r.

[0061] Figure 12 is a flowchart showing the operation of the judgment unit of the turbidity judgment device in the first embodiment.

[0061] FIG13 is a perspective view of the photographed component of the second modified example of the first embodiment.

[0061] Figure 14 is a perspective view of the photographed component of the third modified example of the first embodiment.

[0061] Figure 15 is a perspective view of the photographed component of the fourth modified example of the first embodiment.

[0061] Figure 16 is a simplified cross-sectional view of the hydraulic oil tank, which shows the installation state of the turbidity judgment device in the second embodiment.

[0061] FIG17 is a cross-sectional view of the camera unit in the second embodiment, which shows the cross-section taken along line XVII-XVII of FIG18.

[0061] FIG18 is a cross-sectional view of the camera unit in the second embodiment, which shows the cross-section taken along line XVIII-XVIII of FIG17.

[0061] FIG19 is a cross-sectional view of the camera unit in the second embodiment, which shows the cross-section taken along the XIX-XIX line in FIG18.

[0061] FIG20 is a cross-sectional view of the camera unit in the second embodiment, which shows the cross-section taken along the XX-XX line in FIG18.

[0061] Figure 21 is a top view of the photographed component of the turbidity judgment device in the second embodiment.

[0061] Figure 22 is a judgment image in the turbidity judgment device of the second embodiment.

[0061] Figure 23 is a judgment image in the turbidity judgment device of the second embodiment.

[0061] FIG24 is a cross-sectional view of the camera unit of the first modified example of the second embodiment, showing a cross-section equivalent to FIG18.

[0061] Figure 25 is a top view of the photographed component of the second modified example of the second embodiment.

[0061] Figure 26 is a top view of the photographed component of the second modified example of the second embodiment.

[0061] Figure 27 is a top view of the camera unit, which shows the structure of the turbidity judgment device of the third variation of the second embodiment.

[0061] Figure 28 shows the structure of the turbidity determination device of the first variant of another embodiment.

Implementation Method

[0062] (First Implementation)

[0062] The first embodiment will be described. This embodiment is a turbidity determination device 10 for determining the degree of turbidity of hydraulic oil. The turbidity determination device 10 of this embodiment is also a turbidity determination system 15. The turbidity determination device 10 of this embodiment is installed in the hydraulic oil tank 60 constituting the hydraulic circuit.

[0063] -Hydraulic Oil Tank-

[0063] The hydraulic oil tank 60 of the turbidity judgment device 10 of this embodiment will be described with reference to FIG1.

[0064] The hydraulic oil tank 60 includes a tank body 61, an outlet pipe 62, a return pipe 63, and a filter 64. The hydraulic oil tank 60 stores hydraulic oil. The hydraulic oil stored in the hydraulic oil tank 60 is used to drive hydraulic cylinders and other hydraulic equipment.

[0065] The tank body 61 is a rectangular container. The outlet pipe 62 connects the tank body 61 to the hydraulic pump. The inlet end of the outlet pipe 62 communicates with the internal space of the tank body 61. The filter 64 is connected to the inlet end of the outlet pipe 62. The filter 64 captures sludge and other solids contained in the hydraulic oil flowing into the outlet pipe 62. The return pipe 63 introduces hydraulic oil discharged from the hydraulic equipment into the tank body 61. The outlet end of the return pipe 63 communicates with the internal space of the tank body 61.

[0066] -Structure of the Turbidity Detection Device-

[0066] As shown in Figure 2, the turbidity judgment device 10 includes a main body unit 20, a sheath tube 30, a camera 35, a separating component 31, a photographed component 40, and a judgment unit 25.

[0067] 〈Main Unit〉

[0067] The main body unit 20 is a rectangular box-shaped component. A judgment unit 25 is housed inside the main body unit 20. A display unit 21 is provided on the upper surface of the main body unit 20. The display unit 21 is one or more LED (Light Emitting Diode) lamps.

[0068] 〈Sheath〉

[0068] The sheath 30 is a round tube made of metal or resin. The base end of the sheath 30 is connected to the lower surface of the main body unit 20.

[0069] <Camera>

[0069] As shown in FIG. 3, the camera 35 is formed into a small cylindrical shape. The camera 35 is disposed inside the sheath 30. The end of the camera 35 protrudes from the end of the sheath 30 to the outside. The camera 35 acquires color images. The camera 35 is an imaging unit that acquires images of the photographed component 40.

[0070] The camera 35 includes a light source 36. The light source 36 is a white LED light. The light source 36 is arranged near the end of the camera 35, illuminating light forward from the end of the camera 35. The connecting cable 37 of the camera 35 is electrically connected to the judgment unit 25 inside the main unit 20. The camera 35 transmits image signals to the judgment unit 25 via the connecting cable 37.

[0071] 〈Separation Component〉

[0071] The separating member 31 is a cylindrical metal mesh. The base end of the separating member 31 is installed at the end of the sheath tube 30. The separating member 31 extends forward (downward in Figure 2) from the end of the sheath tube 30. The diameter of the separating member 31 is greater than or equal to the diameter of the sheath tube 30.

[0072] The inner space of the separating component 31 is the judgment space 32. The judgment space 32 is surrounded by a cylindrical metal mesh, i.e., the separating component 31.

[0073] 〈The part being photographed〉

[0073] The photographed component 40 is integrally formed as a thick-walled circular plate. The diameter of the photographed component 40 is, for example, about 13 mm. The material of the photographed component 40 is white resin.

[0074] As shown in Figure 3, the photographed component 40 is configured to block the end of the separating component 31. The photographed component 40 is fixed to the camera 35 via the separating component 31 and the sheath 30. The photographed component 40 cannot move relative to the camera 35. Therefore, the distance L from the camera 35 to the photographed component 40 remains constant.

[0075] As shown in Figures 4 and 5, the photographed component 40 includes a ring portion 41 and two bridge portions 42. The ring portion 41 is an annular portion along the outer edge of the photographed component 40. Each bridge portion 42 is a straight rod-shaped portion that cuts through the inner space of the ring portion 41. The ring portion 41 and each bridge portion 42 are integrally formed.

[0076] In the photographed component 40, the two bridge portions 42 are arranged substantially parallel to each other with a gap between them. The space inside the ring portion 41 is divided into three parts by the two bridge portions 42. The three spaces divided by the two bridge portions 42 are through holes 43 that penetrate the photographed component 40 in the thickness direction.

[0077] 〈Judgment Section〉

[0077] As shown in FIG6, the determination unit 25 includes a CPU 26 mounted on a substrate and a memory device 27 for storing a program for making the CPU 26 work. The memory device 27 is a semiconductor memory.

[0078] The CPU 26 performs color judgment, turbidity judgment, and cause judgment by executing the program stored in the memory device 27. Details of the color judgment, turbidity judgment, and cause judgment will be described later.

[0079] -Setting status of turbidity detection device-

[0079] As shown in Figure 1, the turbidity detection device 10 is installed in the hydraulic oil tank 60. The turbidity detection device 10 is mounted on the tank body 61 of the hydraulic oil tank 60 with the sheath 30 extending downward from the main body unit 20.

[0080] The main unit 20 of the turbidity detection device 10 is located outside the main body 61. The sheath 30 of the turbidity detection device 10 penetrates the top plate of the main body 61 and is inserted into the internal space of the main body 61. The sheath 30 of the turbidity detection device 10 is inserted, for example, through a spare port of the hydraulic oil tank 60. The spare port is a component used to install an additional return pipe 63 on the hydraulic oil tank 60.

[0081] With the turbidity detection device 10 installed in the hydraulic oil tank 60, the end of the sheath 30 containing the camera 35, the partition 31 fixed to the end of the sheath 30, and the camera-captured component 40 are all located below the oil level 65 of the tank body 61. In other words, the end of the sheath 30, the partition 31, and the camera-captured component 40 are immersed in the hydraulic oil stored in the hydraulic oil tank 60.

[0082] The hydraulic oil inside the tank body 61 flows into the judgment space 32 formed between the camera 35 and the photographed component 40 through the metal mesh partition 31. Therefore, the judgment space 32 is filled with the hydraulic oil stored in the hydraulic oil tank 60.

[0083] -Operating status of the turbidity detection device-

[0083] The operation of the turbidity judgment device 10 will be explained.

[0084] In the turbidity judgment device 10, the camera unit, i.e., the camera 35, acquires an image of the photographed component 40 as a judgment image 50. In the turbidity judgment device 10, the judgment unit 25 performs color judgment, turbidity judgment, and cause judgment based on the judgment image 50. The judgment unit 25 performs color judgment and turbidity judgment in sequence. When the judgment unit 25 determines that the turbidity of the hydraulic oil is high (in other words, the state of the hydraulic oil is poor) during the turbidity judgment, the judgment unit 25 performs cause judgment.

[0085] 〈Image for Judgment〉

[0085] As described above, the camera 35 acquires an image of the photographed component 40 as a judgment image 50. The camera 35 sends the acquired judgment image 50 to the judgment unit 25. The judgment unit 25 stores the judgment image 50 received from the camera 35 as a color image in the memory device 27. This color image is a color image with 256 tones each for R (red), G (green), and B (blue). It should be noted that the RGB tones shown here are only one example.

[0086] Figure 7 shows an example of the judgment image 50. The judgment image 50 is an image of the plane of the photographed component 40.

[0087] The light emitted by the light source 36 of the camera 35 shines on the ring portion 41 and the bridge portion 42 of the photographed component 40 and is reflected. Therefore, in the judgment image 50, the portion corresponding to the ring portion 41 and the bridge portion 42 of the photographed component 40 becomes a bright portion 51 with relatively high brightness.

[0088] On the other hand, the light emitted by the light source 36 of the camera 35 passes through the through-hole 43 of the photographed component 40. Since there is a certain distance between the photographed component 40 and the bottom of the hydraulic oil tank 60, the light passing through the through-hole 43 of the photographed component 40 hardly reaches the bottom of the hydraulic oil tank 60. Therefore, in the judgment image 50, the part corresponding to the through-hole 43 of the photographed component 40 becomes a dark area 52 with relatively low brightness.

[0089] It should be noted that the dividing member 31, which is made of metal mesh, will be reflected in the area outside the ring portion 41 of the photographed member 40 in the judgment image 50.

[0090] <Color Judgment Work>

[0090] The color judgment operation is explained. The color judgment operation is "the operation of the judgment unit 25 to judge the color of the hydraulic oil based on the judgment image 50".

[0091] As shown in FIG8, the judgment unit 25 sets four first regions 56 in the color image, i.e., the judgment image 50. The first region 56 is a part of the judgment image 50 and only contains the bright part 51. It should be noted that the number of first regions 56 is only one example, and it can also be one. The judgment unit 25 sets the first region 56 in the part of the judgment image 50 corresponding to the ring part 41 of the photographed member 40. However, the judgment unit 25 may also set the first region 56 in the part of the judgment image 50 corresponding to the bridge part 42 of the photographed member 40.

[0092] The judgment unit 25 determines the color of the hydraulic oil according to ASTM color standards. ASTM color standards classify the color of petroleum products into 16 grades according to ASTM D1500. In this embodiment, the judgment unit 25 classifies the color of the hydraulic oil into four categories: "clear," "yellow," "golden yellow," and "black." Each of "clear," "yellow," "golden yellow," and "black" corresponds to one or more grades of ASTM color standards. It should be noted that the number of color distinctions for hydraulic oil is only one example.

[0093] The memory device 27 of the judgment unit 25 pre-memorizes the respective tone value ranges of RGB for "transparent", "yellow", "golden yellow" and "black", as the reference range for color judgment. The tone value is used to indicate which tone in the 256 tones.

[0094] The ring portion 41 and bridge portion 42 of the photographed component 40 are white. When the camera 35 has acquired the judgment image 50, the judgment space 32 between the camera 35 and the photographed component 40 is filled with hydraulic oil from the hydraulic oil tank 60. The color of the portion in the judgment image 50 corresponding to the ring portion 41 and bridge portion 42 is approximately the same as the color of the hydraulic oil filling the judgment space 32.

[0095] Therefore, the determination unit 25 calculates the average value of each of the RGB tones for all the first regions 56. Then, the determination unit 25 compares the calculated average value of each of the RGB tones related to the first region 56 with the color determination reference range read from the memory device 27 to determine which of the following colors the hydraulic oil color corresponds to: "transparent (n=1)", "yellow (n=2)", "golden yellow (n=3)" or "black (n=4)".

[0096] 〈Benchmark Level Adjustment〉

[0096] In the turbidity judgment operation, the judgment unit 25 uses a reference step adjustment to judge the degree of turbidity of the hydraulic oil, as detailed later. Here, the reference step adjustment will be explained.

[0097] The reference level adjustment is determined based on the judgment image 50 acquired by the camera 35 when the judgment space 32 is filled with hydraulic oil in a non-turbid state. The reference level adjustment ΔVC_r is the difference between the maximum reference level adjustment value VC_max(n) and the minimum reference level adjustment value VC_min(n) in the second region 57 of the judgment image 50 (ΔVC_r = VC_max(n) - VC_min(n)). The second region 57 will be explained further later. The maximum reference level adjustment value VC_max(n) and the minimum reference level adjustment value VC_min(n) used to calculate the reference level adjustment have been determined during the design of the turbidity judgment device 10 and have been pre-recorded in the memory device 27 of the judgment unit 25.

[0098] As shown in FIG9, the second region 57 is a part of the judgment image 50. The second region 57 is a straight line region that is substantially orthogonal to the bridge portion 42 of the photographed component 40. The second region 57 passes through the center of the ring portion 41 of the photographed component 40.

[0099] The second region 57 traverses the ring portion 41, each bridge portion 42, and all the through holes 43. The second region 57 includes two bright portions 51 formed by the ring portion 41, a bright portion 51 formed by each bridge portion 42, and a dark portion 52 formed by each through hole 43. Thus, the second region 57 includes four bright portions 51 and three dark portions 52. In the second region 57, the bright portions 51 and dark portions 52 are arranged alternately from one end to the other.

[0100] Figure 10 shows the tone value of the second region 57 in the judgment image 50, which has been converted into a 256-level grayscale image. This judgment image 50 is acquired by the camera 35 to determine the reference tone difference during the design of the turbidity judgment device 10. This judgment image 50 is acquired by the camera 35 when the judgment space 32 is filled with hydraulic oil in a turbid state.

[0101] The aforementioned grayscale gradation is just one example. In a 256-gradation grayscale, the lowest gradation value "0" corresponds to "black," and the highest gradation value "255" corresponds to "white." The gradation value represents the numerical value of which level of gray from "0 (black)" to "255 (white)." In the grayscale, the lower the gradation value, the closer the gray is to black, while the higher the gradation value, the closer the gray is to white.

[0102] As shown in Figure 10, in the second region 57, the tone value of the bright part 51 is relatively high, and the tone value of the dark part 52 is relatively low. The memory device 27 of the judgment unit 25 stores the maximum tone value of the bright part 51 in the second region 57 as the maximum reference tone value VC_max(n) of the second region 57. The memory device 27 of the judgment unit 25 stores the minimum tone value of the dark part 52 in the second region 57 as the minimum reference tone value VC_min(n) of the second region 57.

[0103] Hereinafter, the maximum reference tone value VC_max(n) and the minimum reference tone value VC_min(n) of the second region 57 vary according to the color of the hydraulic oil. As the color of the hydraulic oil darkens (in other words, from transparent to black), the difference between the maximum reference tone value VC_max(n) and the minimum reference tone value VC_min(n) in the second region 57 gradually decreases. In Figure 10, VC_max(1) and VC_min(1) are the maximum and minimum reference tone values ​​when the color of the hydraulic oil is "transparent (n=1)". VC_max(3) and VC_min(3) are the maximum and minimum reference tone values ​​when the color of the hydraulic oil is "golden (n=3)".

[0104] Therefore, the memory device 27 of the judgment unit 25 stores the maximum reference tone value VC_max(n) and the minimum reference tone value VC_min(n) for the four cases where the color of the hydraulic oil in the unturbid state is "transparent (n=1)", "yellow (n=2)", "golden yellow (n=3)" and "black (n=4)". The number of "groups of reference tone values ​​VC_max(n) and minimum reference tone values ​​VC_min(n)" stored by the memory device 27 of the judgment unit 25 is the same as the number of color distinctions of the hydraulic oil in the color judgment operation.

[0105] 〈Turbidity Judgment Work〉

[0105] The turbidity judgment operation is explained. The turbidity judgment operation is "the operation of the judgment unit 25 to judge the degree of turbidity of the hydraulic oil based on the judgment image 50".

[0106] In the turbidity judgment operation, the judgment unit 25 reads from the memory device 27 the maximum reference tone value VC_max(n) and the minimum reference tone value VC_min(n) corresponding to the color of the hydraulic oil that has been judged in the color judgment operation. For example, if the color of the hydraulic oil is judged to be "yellow (n=2)" in the color judgment operation, the judgment unit 25 reads from the memory device 27 the maximum reference tone value VC_max(2) and the minimum reference tone value VC_min(2) corresponding to "yellow". The judgment unit 25 sets the difference between the maximum reference tone value VC_max(n) and the minimum reference tone value VC_min(n) read from the memory device 27 as the reference tone difference ΔVC_r, (ΔVC_r=VC_max(n)-VC_min(n)).

[0107] As shown in Figure 11, the judgment unit 25 divides the reference order adjustment ΔVC_r into a plurality of levels. Specifically, the judgment unit 25 divides the reference order adjustment ΔVC_r into h levels. "h" is an integer greater than or equal to 2. In this embodiment, the judgment unit 25 divides the reference order adjustment ΔVC_r into ten levels (h=10). The judgment unit 25 uses the following mathematical formula 1 to calculate the threshold ΔVC_s(m) related to the order adjustment. "m" in mathematical formula 1 is an integer from 0 (zero) to h.

[0107] ΔVC_s(m)=m×(ΔVC_r / h) (Mathematical Formula 1)

[0108] The judgment unit 25 sets h levels (LEVEL(m)). Each level is a numerical range represented by the following mathematical formula 2.

[0108]

[0109] In the process of determining turbidity, the determination unit 25 converts the determination image 50 from a color image to a grayscale image. In this embodiment, the determination unit 25 converts the determination image 50 into a 256-level grayscale image.

[0110] The aforementioned grayscale gradation is just one example. In a 256-gradation grayscale, the lowest gradation value "0" corresponds to "black," and the highest gradation value "255" corresponds to "white." The gradation value represents the numerical value of which level of gray from "0 (black)" to "255 (white)." In the grayscale, the lower the gradation value, the closer the gray is to black, while the higher the gradation value, the closer the gray is to white.

[0111] The determination unit 25 determines the maximum tonal value VC1 and the minimum tonal value VC2 of the second region 57 in the determination image 50, which has been converted to grayscale. The maximum tonal value VC1 of the second region 57 is the maximum tonal value of the bright part 51 in the second region 57. The minimum tonal value VC2 of the second region 57 is the minimum tonal value of the dark part 52 in the second region 57. The determination unit 25 calculates the difference between the maximum tonal value VC1 and the minimum tonal value VC2 of the second region 57, and uses this value as the tonal difference ΔVC (=VC1-VC2) between the bright part 51 and the dark part 52 in the second region 57.

[0112] As described above, when the turbidity judgment device 10 is in use, the judgment space 32 between the camera 35 and the photographed component 40 is filled with hydraulic oil stored in the hydraulic oil tank 60. The higher the turbidity of the hydraulic oil filling the judgment space 32, the smaller the tone difference ΔVC (=VC1-VC2) between the bright part 51 and the dark part 52 in the second region 57 of the judgment image 50.

[0113] Therefore, the judgment unit 25 determines which level shown in Figure 11 the calculated level difference ΔVC (=VC1-VC2) between the bright part 51 and the dark part 52 belongs to. Based on the level to which the level difference ΔVC belongs, the judgment unit 25 determines whether the turbidity of the hydraulic oil corresponds to "actually none", "low" or "high".

[0114] An example of the correspondence between these three levels and the level to which the gradation difference ΔVC belongs is shown below. When the gradation difference ΔVC belongs to LEVEL(8) to LEVEL(10), the determination unit 25 determines that "there is substantially no turbidity in the hydraulic oil, and the hydraulic oil is in a good state". When the gradation difference ΔVC belongs to LEVEL(3) to LEVEL(7), the determination unit 25 determines that "the degree of turbidity of the hydraulic oil is low, and the hydraulic oil is in a usable state". When the gradation difference ΔVC belongs to LEVEL(1) to LEVEL(2), the determination unit 25 determines that "the degree of turbidity of the hydraulic oil is high, and the hydraulic oil is in a state unsuitable for use".

[0115] <Cause determination operation>

[0115] When the determination unit 25 has determined that "the degree of turbidity of the hydraulic oil is high, and the hydraulic oil is in a state unsuitable for use", the determination unit 25 performs a cause determination operation. The cause determination operation is "the operation in which the determination unit 25 determines the cause of the turbidity of the hydraulic oil based on the determination image 50".

[0116] In the cause determination operation, the determination unit 25 calculates the average value VC_ave of the gradation values of the second area 57 of the determination image 50. The determination unit 25 sets the maximum reference gradation value VC_max(n) read from the memory device 27 as the reference gradation value for the cause determination operation. The determination unit 25 determines the cause of the turbidity of the hydraulic oil by comparing the calculated average value VC_ave of the gradation values of the second area 57 with the reference gradation value.

[0117] When the hydraulic oil becomes turbid due to the mixing of water, as the degree of turbidity of the hydraulic oil increases, the gradation of the determination image 50 gradually approaches "white" as a whole. Therefore, the gradation of the second area 57 of the determination image 50 rises as a whole. Thus, when the calculated average value VC_ave of the gradation values of the second area 57 is higher than the reference gradation value (VC_max(n) < VC_ave), the determination unit 25 determines that the cause of the turbidity of the hydraulic oil is "mixing of water". ]>

[0118] When the hydraulic oil becomes turbid due to the mixing of particulate solids such as sludge, as the degree of turbidity of the hydraulic oil increases, the gradation of the determination image 50 approaches "black" as a whole. Therefore, the gradation of the second area 57 of the determination image 50 becomes lower as a whole. Thus, when the calculated average value VC_ave of the gradation values of the second area 57 is lower than the reference gradation value (VC_ave < VC_max(n)), the determination unit 25 determines that the cause of the turbidity of the hydraulic oil is "mixing of solids such as sludge".

[0119] -Overall working process of the turbidity detection device--

[0119] Refer to the flowchart in Figure 12 to illustrate the overall process of the operation of the turbidity judgment device 10.

[0120] The judgment unit 25 of the turbidity judgment device 10 executes the program recorded in the memory device 27 by the CPU 26, and performs a series of processes as shown in the flowchart of FIG12. In the flowchart of FIG12, the process of step ST2 is the color judgment work performed by the judgment unit 25, the processes of steps ST3 to ST9 are the turbidity judgment work performed by the judgment unit 25, and the processes of steps ST10 to ST11 are the cause judgment work performed by the judgment unit 25.

[0121] 〈Step ST1〉

[0121] In step ST1, the camera 35 acquires a judgment image 50. Specifically, with the judgment space 32 filled with hydraulic oil from the hydraulic tank 60, the light source 36 of the camera 35 illuminates the photographed component 40, and the camera 35 takes a picture of the photographed component 40. The camera 35 sends the acquired judgment image 50 to the judgment unit 25. The judgment unit 25 stores the judgment image 50 sent from the camera 35 as a color image in the memory device 27. This color image is a color image with 256 tones each for R (red), G (green), and B (blue). When step ST1 is completed, the judgment unit 25 proceeds to step ST2.

[0122] 〈Step ST2〉

[0122] Step ST2 is a color judgment operation performed by the judgment unit 25. The details of the color judgment operation are as described above. In step ST2, the judgment unit 25 determines which of the following colors of hydraulic oil filling the judgment space 32 corresponds to: "transparent (n=1)", "yellow (n=2)", "golden yellow (n=3)" and "black (n=4)" based on the four first regions 56 set in the color image, i.e., the judgment image 50.

[0123] The color of the hydraulic oil filling the judgment space 32 is the same as the color of the hydraulic oil in the hydraulic oil tank 60. Therefore, in the process of step ST2, the judgment unit 25 judges the color of the hydraulic oil in the hydraulic oil tank 60. When the process of step ST2 ends, the judgment unit 25 performs the process of step ST3.

[0124] 〈Step ST3〉

[0124] In the process of step ST3, the judgment unit 25 begins to perform turbidity judgment.

[0125] In step ST3, the determination unit 25 sets a reference level adjustment ΔVC_r. Specifically, the determination unit 25 reads from the memory device 27 the maximum reference level adjustment value VC_max(n) and the minimum reference level adjustment value VC_min(n) corresponding to the color of the hydraulic oil determined in step ST2. The determination unit 25 sets the difference between the maximum reference level adjustment value VC_max(n) and the minimum reference level adjustment value VC_min(n) read from the memory device 27 as the reference level adjustment ΔVC_r (ΔVC_r = VC_max(n) - VC_min(n)). When step ST3 ends, the determination unit 25 proceeds to step ST4.

[0126] 〈Step ST4〉

[0126] In the process of step ST4, the determination unit 25 uses the reference level adjustment ΔVC_r set in the process of step ST3 to perform the operation shown in the aforementioned mathematical formula 1, thereby setting a plurality of (ten in this embodiment) levels (LEVEL(m)). When the process of step ST4 ends, the determination unit 25 performs the process of step ST5.

[0127] 〈Step ST5〉

[0127] In step ST5, the determination unit 25 converts the color image acquired by the camera 35 in step ST1, i.e., the determination image 50, into a 256-level grayscale image. When step ST5 ends, the determination unit 25 performs step ST6.

[0128] 〈Step ST6〉

[0128] In step ST6, the determination unit 25 determines the maximum tone value VC1 and the minimum tone value VC2 of the second region 57 in the determination image 50, which was converted to grayscale image in step ST5. The determination unit 25 calculates the difference between the maximum tone value VC1 and the minimum tone value VC2 of the second region 57, and uses this value as the tone difference ΔVC (=VC1-VC2) between the bright part 51 and the dark part 52 in the second region 57. When step ST6 ends, the determination unit 25 performs step ST7.

[0129] 〈Step ST7〉

[0129] In step ST7, the determination unit 25 determines whether the condition "ΔVC_s(10) < ΔVC" is met. If the condition is met, the pitch difference ΔVC between the bright part 51 and the dark part 52 in the second region 57 exceeds LEVEL(10). In step ST1, if the determination image 50 acquired by the camera 35 is normal, the pitch difference ΔVC will not exceed LEVEL(10). Therefore, when the pitch difference ΔVC exceeds LEVEL(10), for example, an abnormal situation may occur such as air bubbles adhering to the photographed part 40, and the state of the hydraulic oil may not be properly determined based on the determination image 50 acquired by the camera 35 in step ST1.

[0130] Therefore, when the condition "ΔVC_s(10)<ΔVC" is met, the determination unit 25 performs the processing from step ST1 to step ST6 again. That is, in this case, the determination unit 25 performs color determination using the determination image 50 acquired again by the camera 35, and calculates the tone difference ΔVC between the bright part 51 and the dark part 52 in the second region 57 of the determination image 50. On the other hand, when this condition is not met, the determination unit 25 performs the processing of step ST8.

[0131] 〈Step ST8〉

[0131] In step ST8, the determination unit 25 determines whether the condition "ΔVC_s(7) < ΔVC" is met. If the condition is met, the level difference ΔVC between the bright part 51 and the dark part 52 in the second region 57 is between LEVEL(8) and LEVEL(10). If the level difference ΔVC is between LEVEL(8) and LEVEL(10), the turbidity of the hydraulic oil is equivalent to "substantially none". On the other hand, if the condition is met, the determination unit 25 performs step ST12. On the other hand, if the condition is not met, the determination unit 25 performs step ST9.

[0132] 〈Step ST9〉

[0132] In the process of step ST9, the determination unit 25 determines whether the condition of "ΔVC_s(2) < ΔVC" is satisfied. When this condition is satisfied, the gradation difference ΔVC between the bright part 51 and the dark part 52 in the second region 57 belongs to the range between LEVEL(3) and LEVEL(7). When the gradation difference ΔVC belongs to the range between LEVEL(3) and LEVEL(7), the turbidity of the hydraulic oil is equivalent to "substantially none". Therefore, when this condition is satisfied, the determination unit 25 performs the process of step ST13. On the other hand, when this condition is not satisfied, the determination unit 25 performs the process of step ST10.

[0133] 〈Step ST10〉

[0133] In the process of step ST9, when the condition of "ΔVC_s(2) < ΔVC" is not satisfied, the gradation difference ΔVC between the bright part 51 and the dark part 52 in the second region 57 belongs to LEVEL(1) to LEVEL(2). When the gradation difference ΔVC belongs to the range between LEVEL(1) and LEVEL(2), the turbidity of the hydraulic oil is equivalent to "high". When the turbidity of the hydraulic oil is equivalent to "high", the determination unit 25 determines that "the turbidity of the hydraulic oil is high and the hydraulic oil is in a state unsuitable for use". In the process of step ST10, the determination unit 25 starts the cause determination work.

[0134] In the process of step ST10, the determination unit 25 uses the determination image 50 converted into a grayscale image in the process of step ST5 as an object, and calculates the average value VC_ave of the gradation values of the second region 57. When the process of step ST10 ends, the determination unit 25 performs the process of step ST11.

[0135] 〈Step ST11〉

[0135] In the process of step ST11, the determination unit 25 sets the maximum reference gradation value VC_max(n) read from the memory device 27 in the process of step ST3 as the reference gradation value for the cause determination work. The determination unit 25 determines whether the condition of "VC_max(n) < VC_ave" is satisfied.

[0136] When the condition of "VC_max(n) < VC_ave" is satisfied, the overall gradation of the second region 57 of the determination image 50 is close to "white". Therefore, the determination unit 25 determines that the cause of the hydraulic oil turbidity is "mixing of water" and performs the process of step ST14.

[0137] On the other hand, when the condition "VC_max(n) < VC_ave" does not hold, it is determined that the overall tone of the second region 57 of the determination image 50 is close to "black". Therefore, the determination unit 25 determines that the cause of the hydraulic oil turbidity is "mixing of solids such as sludge", and performs the process of step ST15.

[0138] 〈Step ST12〉

[0138] The process of step ST12 is executed when it is determined in the process of step ST8 that the turbidity degree of the hydraulic oil is equivalent to "substantially none".

[0139] In the process of step ST12, the determination unit 25 performs a first display operation. The first display operation is an operation for causing the information of "the hydraulic oil is substantially not turbid and the hydraulic oil is in a good state" to be displayed on the display unit 21 of the main body unit 20. As this first display operation, the determination unit 25 performs "an operation for causing the display unit 21, that is, the LED lamp, to light up green". It should be noted that the color of the light emitted by the display unit 21 is only an example.

[0140] 〈Step ST13〉

[0140] The process of step ST13 is executed when it is determined in the process of step ST9 that the turbidity degree of the hydraulic oil is equivalent to "low".

[0141] In the process of step ST13, the determination unit 25 performs a second display operation. The second display operation is an operation for causing the information of "the turbidity degree of the hydraulic oil is low and the hydraulic oil is in a state where it can be used" to be displayed on the display unit 21 of the main body unit 20. As this second display operation, the determination unit 25 performs, for example, "an operation for causing the display unit 21, that is, the LED lamp, to light up orange". It should be noted that the color of the light emitted by the display unit 21 is only an example.

[0142] 〈Step ST14〉

[0142] The process of step ST14 is executed when it is determined in the process of step ST11 that the cause of the hydraulic oil turbidity is "mixing of water".

[0143] In the process of step ST14, the determination unit 25 performs a third display operation. The third display operation is an operation for displaying on the display unit 21 of the main body unit 20 the information that the cause of the hydraulic oil turbidity is "mixing of water". As this third display operation, the determination unit 25 performs, for example, "an operation for causing the display unit 21, that is, the LED lamp, to alternately light up red and blue". It should be noted that the color of the light emitted by the display unit 21 is only an example.

[0144] 〈Step ST15〉

[0144] Step ST15 is performed when it is determined in step ST11 that the cause of the hydraulic oil turbidity is "the contamination of solid matter".

[0145] In the process of step ST15, the determination unit 25 performs a fourth display operation. The fourth display operation is to display information on the display unit 21 of the main unit 20 that the cause of the hydraulic oil turbidity is "the contamination of solid matter such as sludge". As this fourth display operation, the determination unit 25 performs, for example, "the operation of turning the display unit 21, i.e., the LED light, red". It should be noted that the color of the light emitted by the display unit 21 is only one example.

[0146] -Characteristics of the first implementation form (1)-

[0146] In the turbidity judgment device 10 of this embodiment, the camera 35 acquires an image of the photographed component 40 as a judgment image 50. Hydraulic oil, which is the object of turbidity judgment, exists between the camera 35 and the photographed component 40. The tone difference between the bright areas 51 and the dark areas 52 in the judgment image 50 varies depending on the degree of turbidity of the hydraulic oil present between the camera 35 and the photographed component 40. Therefore, the judgment unit 25 judges the degree of turbidity of the hydraulic oil based on the tone difference between the bright areas 51 and the dark areas 52 in the judgment image 50.

[0147] It should be noted that, in the description of this embodiment, "gradient difference" is an indicator representing "difference in color intensity". The meaning of "gradient difference" in grayscale images is essentially the same as the meaning of "contrast".

[0148] As long as the hydraulic oil to be judged for turbidity exists between the camera unit 35 and the photographed component 40, the turbidity judgment device 10 of this embodiment can judge the degree of turbidity of the hydraulic oil. Therefore, if the turbidity judgment device 10 is used, the degree of turbidity of the hydraulic oil can be judged without collecting a test sample of the hydraulic oil from the hydraulic equipment.

[0149] In particular, the turbidity determination device 10 of this embodiment determines the degree of turbidity of the hydraulic oil while it is installed in the hydraulic oil tank 60. It can continuously determine the condition of the hydraulic oil actually in use and quickly notify the user and manager of the hydraulic equipment when the condition of the hydraulic oil deteriorates. Therefore, according to the turbidity determination device 10 of this embodiment, information can be provided to the user or manager of the hydraulic equipment to help prevent the hydraulic equipment from malfunctioning due to continuous use of deteriorated hydraulic oil.

[0150] -Characteristics of the first implementation form (2)-

[0150] In the turbidity determination device 10 of this embodiment, the determination unit 25 determines the color of the hydraulic oil by color determination. Furthermore, the determination unit 25 determines the degree of turbidity of the hydraulic oil by comparing a reference level difference ΔVC_r corresponding to the color of the hydraulic oil with the level difference ΔVC of the bright portion 51 and dark portion 52 in the determination image 50 acquired by the imaging unit 35. Therefore, the turbidity determination device 10 of this embodiment can appropriately determine the degree of turbidity of the hydraulic oil even if the color of the hydraulic oil changes during use.

[0151] In particular, the judgment unit 25 of this embodiment performs color judgment based on a first region 56 that contains only the bright portion 51 of the judgment image 50. In this embodiment, the ring portion 41 of the photographed component 40 forms the bright portion 51 of the judgment image 50, and the ring portion 41 of the photographed component 40 is white. Therefore, the color of the first region 56 of the judgment image 50 is approximately the same as the color of the hydraulic oil filling the judgment space 32. Therefore, in the turbidity judgment device 10 of this embodiment, the color of the hydraulic oil stored in the hydraulic oil tank 60 can be accurately determined by the color judgment operation of the judgment unit 25.

[0152] -Characteristics of the first implementation form (3)-

[0152] In the turbidity judgment device 10 of this embodiment, the judgment unit 25 judges the degree of turbidity of the hydraulic oil based on the level difference ΔVC between the bright part 51 and the dark part 52 in the second region 57 of the judgment image 50 during the turbidity judgment operation.

[0153] The second region 57 of the judgment image 50 used in the turbidity judgment work includes a plurality of bright areas 51 and a plurality of dark areas 52. In this embodiment, the judgment unit 25 sets the difference between the maximum value of the tone value of the bright areas 51 in the second region 57, i.e., the maximum tone value VC1, and the minimum value of the tone value of the dark areas 52 in the second region 57, i.e., the minimum tone value VC2, as the tone difference ΔVC between the bright areas 51 and the dark areas 52 in the second region 57 (=VC1-VC2). Therefore, according to this embodiment, the tone difference ΔVC between the bright areas 51 and the dark areas 52 in the second region 57 can be accurately calculated, and as a result, the degree of turbidity of the hydraulic oil can be accurately judged.

[0154] -Characteristics of the first implementation form (4)-

[0154] In the turbidity determination device 10 of this embodiment, when the turbidity of the hydraulic oil is high, the determination unit 25 performs cause determination. In the cause determination, the determination unit 25 determines whether the cause of the turbidity of the hydraulic oil is "the mixing of water" or "the mixing of solid matter".

[0155] The countermeasures to be taken differ depending on whether the cause of hydraulic oil turbidity is "water contamination" or "solid contamination". Therefore, the turbidity judgment device 10 of this embodiment can provide the user or manager of the hydraulic equipment with the information needed to determine the countermeasures to be taken by judging the cause of hydraulic oil turbidity.

[0156] -Characteristics of the first implementation form (5)-

[0156] Therefore, when the distance from the camera 35 to the photographed component 40 changes, the correlation between the "turbidity of the hydraulic oil" and the "tone difference ΔVC between the bright part 51 and the dark part 52 in the judgment image 50" will change. On the other hand, in the turbidity judgment device 10 of this embodiment, the photographed component 40 is fixed to the sheath 30 by the separating member 31, and the distance L from the camera 35 to the photographed component 40 remains constant. Therefore, in the turbidity judgment device 10 of this embodiment, the correlation between the "turbidity of the hydraulic oil" and the "tone difference ΔVC between the bright part 51 and the dark part 52 in the judgment image 50" can be kept constant, and the turbidity of the hydraulic oil can be accurately judged.

[0157] -Characteristics of the first implementation form (6)-

[0157] In the turbidity judgment device 10, the photographed component 40 may be formed as a flat plate without through holes 43, and white and black areas may be formed on the upper surface of the photographed component 40, using the black area to form the dark area 52 of the judgment image 50. However, in this case, if there are white foreign objects on the black area of ​​the photographed component 40, the judgment unit 25 may incorrectly judge the tone value of the dark area 52 in the judgment image 50 as higher than the actual value, which may result in an incorrect judgment of the turbidity of the hydraulic oil.

[0158] In contrast, in the turbidity judgment device 10 of this embodiment, the through-hole 43 of the photographed component 40 forms the dark area 52 of the judgment image 50. Foreign matter will not remain in the through-hole 43 of the photographed component 40. Therefore, the judgment unit 25 can accurately judge the tone value of the dark area 52 of the judgment image 50, and as a result, it can accurately judge the degree of turbidity of the hydraulic oil.

[0159] -Characteristics of the first implementation form (7)-

[0159] If a foreign object enters the judgment space 32 between the camera 35 and the photographed component 40, the foreign object may be reflected in the judgment image 50. If an object other than the photographed component 40 is reflected in the judgment image 50, the judgment results of the color of the hydraulic oil in the color judgment operation, the judgment results of the degree of turbidity of the hydraulic oil in the turbidity judgment operation, and the judgment results of the cause of turbidity of the hydraulic oil in the cause judgment operation may all become inaccurate.

[0160] On the other hand, in the turbidity judgment device 10 of this embodiment, the judgment space 32 between the camera 35 and the photographed component 40 is surrounded by a metal mesh partition member 31. Therefore, while allowing hydraulic oil to enter and exit the judgment space 32, it is possible to prevent larger foreign objects from entering the judgment space 32. Therefore, according to the turbidity judgment device 10 of this embodiment, the possibility of misjudgment caused by foreign objects entering the judgment space 32 can be reduced. As a result, it is possible to accurately judge the color of the hydraulic oil in color judgment work, judge the degree of turbidity of the hydraulic oil in turbidity judgment work, and judge the cause of turbidity of the hydraulic oil in cause judgment work.

[0161] -Variations of the first embodiment-

[0161] The turbidity determination device 10 of the first embodiment described above can also be modified as follows. It should be noted that the following modifications can be appropriately combined or replaced as long as they do not impair the function of the turbidity determination device 10.

[0162] 〈First Variation〉

[0162] The color of the photographed component 40 is not limited to white. However, the color of the part of the photographed component 40 that forms the bright part 51 is preferably a color with high brightness.

[0163] 〈Second Variation〉

[0163] The shape of the bridge portion 42 of the photographed component 40 is not limited to a straight rod shape. For example, as shown in FIG13, the bridge portion 42 may also be formed in an X-shape. In the photographed component 40 shown in FIG13, four through holes 43 divided by the X-shaped bridge portion 42 are formed on the inner side of the ring portion 41.

[0164] 〈Third Variation〉

[0164] The photographed component 40 may also be a flat component without a through hole 43.

[0165] As shown in Figures 14 and 15, in the photographed component 40 of this modified example, a white area 44 and a black area 45 are formed on the surface opposite to the camera unit 35. The white area 44 forms the bright part 51 of the judgment image 50. The black area 45 forms the dark part 52 of the judgment image 50.

[0166] In the photographed component 40 shown in FIG14, the surface opposite to the camera 35 is divided into a white area 44 and a black area 45. In the photographed component 40 shown in FIG15, on the surface opposite to the camera 35, circular white areas 44 and black areas 45 are arranged alternately in a concentric circle.

[0167] 〈Fourth Variation〉

[0167] The turbidity determination device 10 of this embodiment can be configured to display the determination results obtained by the determination unit 25 in the turbidity determination and cause determination operations on an external device such as a smartphone. In this case, the turbidity determination device 10 is configured to be able to wirelessly communicate with an external device such as a smartphone.

[0168] Second Implementation Form

[0168] The turbidity determination device 10 of the second embodiment will be described. Like the turbidity determination device 10 of the first embodiment, the turbidity determination device 10 of this embodiment is also a turbidity determination system 15.

[0169] As shown in FIG. 16, the turbidity determination device 10 of this embodiment includes a camera unit 70 and a determination unit 80. The camera unit 70 and the determination unit 80 are electrically connected by a connecting cable 85. The camera unit 70 and the determination unit 80 communicate with each other via the connecting cable 85. The camera unit 70 is disposed midway in the return pipe 63 connected to the hydraulic oil tank 60. The return pipe 63 is an oil pipe for supplying hydraulic oil.

[0170] -Camera Unit--

[0170] Regarding the camera unit 70, please refer to Figures 17 to 21 for appropriate explanation. It should be noted that in the following explanation, "up", "down", "right", "left", "front" and "rear" refer to the directions shown in Figures 17 and 18.

[0171] As shown in Figures 17 and 18, the camera unit 70 includes a housing 71. Inside the housing 71 are a camera 35, a first light source 36a, a second light source 36b, a path block 73, a photographed component 40, and a substrate 72. Furthermore, a first connector component 75a and a second connector component 75b are connected to the path block 73.

[0172] 〈Shell>

[0172] The housing 71 is a box-shaped component with a cuboid shape. As shown in FIG18, the housing 71 includes a housing body 71a and a housing cover 71b. The housing cover 71b is arranged on the front side of the housing body 71a and covers the opening of the housing body 71a. As shown in FIG17, a connector 77 for connecting the connecting cable 85 is provided on the side of the housing 71 (the right side in this embodiment).

[0173] The shell body 71a and shell cover 71b constituting the shell 71 are made of opaque synthetic resin. It should be noted that one of the shell body 71a and shell cover 71b, or both of the shell body 71a and shell cover 71b, may be made of metal.

[0174] 〈Substrate〉

[0174] The substrate 72 is a rectangular, thick plate-shaped component. The substrate 72 is made of a transparent synthetic resin (e.g., acrylic resin).

[0175] As shown in Figures 17 and 18, the substrate 72 is housed within the housing body 71a. The substrate 72 is fixed to the bottom of the housing body 71a in a posture that is approximately parallel to the bottom of the housing body 71a. The substrate 72 is arranged in the center of the housing body 71a in the left-right direction with its long side pointing vertically.

[0176] 〈The part being photographed〉

[0176] As shown in FIG21, the photographed component 40 in this embodiment is a rectangular sheet-like component. The material of the photographed component 40 is an opaque white synthetic resin.

[0177] A judgment pattern 46 is depicted on the surface of the photographed component 40. In this embodiment, the judgment pattern 46 is a black grid pattern. The judgment pattern 46 is composed of a plurality of slightly thick black vertical lines arranged at certain intervals and a plurality of slightly thick black horizontal lines arranged at certain intervals.

[0178] In the photographed component 40 of this embodiment, the black judgment pattern 46 forms the dark part 52 of the judgment image 50, and the white part other than the judgment pattern 46 forms the bright part 51 of the judgment image 50.

[0179] As shown in Figures 18 and 20, the sheet-like photographed component 40 is attached to the front surface of the substrate 72 with the face depicted with the judgment pattern 46 facing forward. The photographed component 40 is arranged at the center of the substrate 72 in both the vertical and horizontal directions.

[0180] 〈Path Block〉

[0180] The passage block 73 is an intermediate component arranged between the photographed component 40 and the camera 35.

[0181] The passage block 73 is a cuboid-shaped block component. The passage block 73 is a hexahedron with six sides. Each side of the passage block 73 is substantially flat. In the passage block 73, opposite pairs of sides are substantially parallel. The passage block 73 is made of a transparent synthetic resin (e.g., acrylic resin).

[0182] As shown in Figures 18 and 19, an oil passage 74 for allowing hydraulic oil to flow is formed on the passage block 73. The oil passage 74 is a through hole extending along the length direction (vertical direction in Figure 18) of the passage block 73. The cross-section of the oil passage 74 is circular. One end of the oil passage 74 opens on one end face (upper end face in Figure 18) of the passage block 73. The other end of the oil passage 74 opens on the other end face (lower end face in Figure 18) of the passage block 73.

[0183] As shown in FIG18, the access block 73 is arranged in front of the substrate 72. The access block 73 is in close contact with the photographed part 40 attached to the substrate 72. As shown in FIG20, the access block 73 covers the entire photographed part 40.

[0184] As shown in FIG18, in the passage block 73, the rear surface that is in close contact with the photographed component 40 is the first side surface 73a, and the front surface opposite to the photographed component 40 is the second side surface 73b. In the passage block 73, the oil passage 74 is arranged between the mutually parallel first side surface 73a and second side surface 73b.

[0185] 〈Camera〉

[0185] The camera 35 in this embodiment is the same as the camera 35 in the first embodiment 1, and is an imaging unit that acquires images of the photographed component 40. The camera 35 in this embodiment includes a lens 35a and acquires color images.

[0186] As shown in Figures 17 and 18, the camera 35 is fixed to the housing 71b by the support plate 76. The camera 35 is electrically connected to the connector 77.

[0187] Inside the housing 71, a camera 35 is positioned in front of the passage block 73. The lens 35a of the camera 35 faces the second side 73b of the passage block 73. As shown in FIG19, the lens 35a of the camera 35 is opposite to the area near the center in the vertical direction of the second side 73b.

[0188] The camera 35 faces the second side 73b of the passage block 73 and acquires an image of the photographed component 40 arranged on the opposite side of the passage block 73 as a judgment image 50. In other words, the camera 35 acquires an image of the photographed component 40 as observed from the second side 73b of the passage block 73 as a judgment image 50.

[0189] 〈First Light Source, Second Light Source〉

[0189] Both the first light source 36a and the second light source 36b are light-emitting light sources 36. The first light source 36a and the second light source 36b are white LED lights.

[0190] Both the first light source 36a and the second light source 36b are fixed together with the camera 35 on the support plate 76. The first light source 36a and the second light source 36b are electrically connected to the connector 77.

[0191] Inside the housing 71, the first light source 36a, the camera 35, and the second light source 36b are arranged in a row along the extension direction of the oil passage 74 (the vertical direction in Figures 17 and 18). In Figures 17 and 18, the first light source 36a is positioned above the camera 35, and the second light source 36b is positioned below the camera 35.

[0192] 〈First Connector Component, Second Connector Component〉

[0192] As shown in Figures 18 and 19, the first connector component 75a and the second connector component 75b are respectively metal cylindrical components.

[0193] The first connector component 75a penetrates the upper side of the housing body 71a in FIG. 18. One end of the first connector component 75a (the lower end in FIG. 18) is inserted into the opening of the oil passage 74, which is located on the upper surface of the passage block 73 in FIG. 18. The other end of the first connector component 75a (the upper end in FIG. 18) is connected to the return pipe 63 for the flow of hydraulic oil.

[0194] The second connector component 75b penetrates the lower side of the housing body 71a in FIG. 18. One end of the second connector component 75b (the upper end in FIG. 18) is inserted into the opening of the oil passage 74 in FIG. 18 located on the lower surface of the passage block 73. The other end of the second connector component 75b (the lower end in FIG. 18) is connected to the return pipe 63 for the flow of hydraulic oil.

[0195] - Judgment Unit--

[0195] As shown in FIG16, the judgment unit 80 includes a judgment unit 25 and a display unit 21.

[0196] 〈Judgment Section〉

[0196] The determination unit 25 of this embodiment is configured the same as that of the determination unit 25 of the first embodiment. Specifically, the determination unit 25 of this embodiment includes a CPU 26 and a memory device 27.

[0197] The judgment unit 25 of this embodiment performs the same operation as the judgment unit 25 of the first embodiment. Specifically, the judgment unit 25 of this embodiment uses the judgment image 50 to perform color judgment, turbidity judgment, and cause judgment.

[0198] 〈Display Section〉

[0198] The display unit 21 in this embodiment is the same as the display unit 21 in the first embodiment, and consists of one or more LED lights.

[0199] -Operating status of the turbidity detection device-

[0199] The operation of the turbidity judgment device 10 will be explained.

[0200] The turbidity detection device 10 performs the operation described later while the hydraulic oil is passing through the camera unit 70. The hydraulic oil flowing through the return pipe 63 flows into the oil passage 74 of the passage block 73 through the first connector component 75a and flows through the oil passage 74. The hydraulic oil that has passed through the oil passage 74 flows out of the camera unit 70 through the second connector component 75b and flows back into the hydraulic oil tank 60 through the return pipe 63.

[0201] In the turbidity judgment device 10, the camera unit, i.e., the camera 35, acquires an image of the photographed component 40 as a judgment image 50. In the turbidity judgment device 10, the judgment unit 25 performs color judgment, turbidity judgment, and cause judgment based on the judgment image 50. The judgment unit 25 performs color judgment and turbidity judgment in sequence. When the judgment unit 25 determines that the turbidity of the hydraulic oil is high (in other words, the condition of the hydraulic oil is poor) during the turbidity judgment, the judgment unit 25 performs cause judgment. These operations are the same as those performed by the turbidity judgment device 10 in the first embodiment.

[0202] 〈Image for Judgment〉

[0202] As described above, the camera 35 acquires an image of the photographed component 40 as a judgment image 50. The camera 35 sends the acquired judgment image 50 to the judgment unit 25. The judgment unit 25 stores the judgment image 50 received from the camera 35 as a color image in the memory device 27. This color image is a color image with 256 tones each for R (red), G (green), and B (blue). It should be noted that the RGB tones shown here are only one example.

[0203] The light emitted by the first light source 36a and the second light source 36b passes through the transparent passage block 73, illuminates the photographed component 40, and is reflected. The light that illuminates the photographed component 40 and is reflected passes through the passage block 73 and the hydraulic oil flowing through the oil passage 74, and enters the camera 35.

[0204] Figures 22 and 23 show an example of a judgment image 50 acquired by the camera 35. The judgment image 50 is an image of the plane of the photographed component 40. The portion corresponding to the black judgment pattern 46 drawn on the surface of the photographed component 40 becomes the dark area 52 with relatively low brightness in the judgment image 50. Moreover, the portion corresponding to the white area on the surface of the photographed component 40 other than the judgment pattern 46 becomes the bright area 51 with relatively high brightness in the judgment image 50.

[0205] <Color Judgment Work>

[0205] The color judgment operation is explained. The color judgment operation is "the operation of the judgment unit 25 to judge the color of the hydraulic oil based on the judgment image 50".

[0206] As shown in FIG22, the judgment unit 25 sets four first regions 56 in the color image, i.e., the judgment image 50. The first region 56 is a part of the judgment image 50 and only contains the bright part 51. It should be noted that the number of first regions 56 is only one example, and it can also be one. The judgment unit 25 sets the first region 56 in the portion of the judgment image 50 that corresponds to the area other than the judgment pattern 46 of the photographed component 40.

[0207] The determination unit 25 determines the color of the hydraulic oil based on ASTM colorimetry. The process for determining the color of the hydraulic oil is the same as that performed by the determination unit 25 in the first embodiment. Specifically, the determination unit 25 calculates the average value of the tone values ​​of each of the RGB values ​​for all the first regions 56. Furthermore, based on the calculated average value of the tone values ​​of each of the RGB values ​​related to the first regions 56, the determination unit 25 determines whether the color of the hydraulic oil is "transparent", "yellow", "golden yellow", or "black".

[0208] 〈Turbidity Judgment Work〉

[0208] The turbidity judgment operation is explained. The turbidity judgment operation is "the operation of the judgment unit 25 to judge the degree of turbidity of the hydraulic oil based on the judgment image 50".

[0209] The turbidity judgment operation performed by the judgment unit 25 in this embodiment is the same as that performed by the judgment unit 25 in the first embodiment. The second region 57 set by the judgment unit 25 in this embodiment in the turbidity judgment operation is different from the second region 57 set by the judgment unit 25 in the first embodiment in the turbidity judgment operation.

[0210] The second region 57 set by the judgment unit 25 of this embodiment in the turbidity judgment operation will be described with reference to FIG23.

[0211] The second region 57 is a part of the judgment image 50. The second region 57 is a straight line area located in the center of the judgment graphic 46 that has been projected into the judgment image 50 in the left-right direction. The second region 57 is the part of the judgment graphic 46 that has been projected into the judgment image 50 that overlaps with the oil passage 74 when viewed from the second side 73b side of the passage block 73.

[0212] The second region 57 runs through a plurality of horizontal lines that constitute the judgment pattern 46. Therefore, in the second region 57, the dark area 52 formed by the judgment pattern 46 and the bright area 51 formed by the part of the photographed component 40 other than the judgment pattern 46 appear alternately from one end of the second region 57 to the other end.

[0213] In the turbidity determination operation, the determination unit 25 of the present embodiment is the same as the determination unit 25 of the first embodiment, calculates the gradation difference ΔVC (= VC1 - VC2) between the bright part 51 and the dark part 52 in the second region 57, and determines which grade shown in FIG. 11 the calculated gradation difference ΔVC belongs to. The determination unit 25 determines which of "substantially none", "low", and "high" the turbidity of the hydraulic oil corresponds to based on the grade to which the gradation difference ΔVC belongs.

[0214] <Cause determination operation>

[0214] When the determination unit 25 determines that "the turbidity of the hydraulic oil is high and the hydraulic oil is in an unsuitable state for use", the determination unit 25 performs a cause determination operation. The cause determination operation is "the operation in which the determination unit 25 determines the cause of the turbidity of the hydraulic oil based on the determination image 50".

[0215] In the cause determination operation, the determination unit 25 of the present embodiment is the same as the determination unit 25 of the first embodiment, calculates the average value VC_ave of the gradation values of the second region 57 of the determination image 50, and compares the calculated average value VC_ave of the gradation values of the second region 57 with a reference gradation value to determine the cause of the turbidity of the hydraulic oil.

[0216] Specifically, when the average value VC_ave of the gradation values in the second region 57 is higher than the reference gradation value (VC_max(n) < VC_ave), the determination unit 25 of the present embodiment determines that the cause of the turbidity of the hydraulic oil is "mixing of water". When the average value VC_ave of the gradation values in the second region 57 is lower than the reference gradation value (VC_ave < VC_max(n)), the determination unit 25 of the present embodiment determines that the cause of the turbidity of the hydraulic oil is "mixing of solids such as sludge".

[0217] -Overall process of the operation of the turbidity determination device-

[0217] The overall process of the operation of the turbidity determination device 10 of the present embodiment is the same as the overall process of the operation of the turbidity determination device 10 of the first embodiment shown in the flowchart of FIG. 12. The turbidity determination device 10 of the present embodiment performs a color determination operation, a turbidity determination operation, and a cause determination operation, and causes the display unit 21 composed of LED lights to display the results obtained from the turbidity determination operation and the cause determination operation.

[0218] -Feature (1) of the second embodiment-

[0218] Similar to the turbidity determination device 10 of the first embodiment, the turbidity determination device 10 of this embodiment can determine the degree of turbidity of the hydraulic oil as long as the hydraulic oil to be determined is present between the camera unit 35 and the photographed component 40. Therefore, if the turbidity determination device 10 is used, the degree of turbidity of the hydraulic oil can be determined without collecting a test sample of the hydraulic oil from the hydraulic equipment.

[0219] In particular, the turbidity detection device 10 of this embodiment determines the turbidity of the hydraulic oil returning to the hydraulic oil tank 60 through the return pipe 63. It can continuously determine the condition of the hydraulic oil actually in use and quickly notify the user and manager of the hydraulic equipment when the condition of the hydraulic oil deteriorates. Therefore, according to the turbidity detection device 10 of this embodiment, information can be provided to the user or manager of the hydraulic equipment to help prevent hydraulic equipment failure due to continuous use of deteriorated hydraulic oil.

[0220] The turbidity determination device 10 according to this embodiment can achieve the same effect as the turbidity determination device 10 of the first embodiment.

[0221] -Features of the second implementation form (2)-

[0221] In the turbidity determination device 10 of this embodiment, the hydraulic oil that is the object of turbidity determination flows through the oil passage 74 formed in the passage block 73, and the camera 35 and the photographed component 40 are arranged outside the passage block 73. Therefore, in the turbidity determination device 10 of this embodiment, the hydraulic oil that is the object of turbidity determination does not come into contact with the photographed component 40 and the camera 35.

[0222] Therefore, if foreign matter contained in the hydraulic oil adheres to the photographed component 40 or the camera 35, it is impossible to obtain an image 50 that accurately reflects the state of the hydraulic oil, and the state of the hydraulic oil may be misjudged.

[0223] On the other hand, in the turbidity determination device 10 of this embodiment, since the hydraulic oil, which is the object of turbidity determination, does not come into contact with the photographed component 40 and the camera 35, foreign matter contained in the hydraulic oil will not adhere to the photographed component 40 and the camera unit 35. Therefore, according to this embodiment, the accuracy of determining the state of the hydraulic oil can be improved.

[0224] -Features of the second implementation form (3)-

[0224] In the turbidity determination device 10 of this embodiment, the photographed component 40 contacts the first side surface 73a of the passage block 73, which is a plane. The camera 35 faces the second side surface 73b of the passage block 73 and acquires an image of the photographed component 40 arranged on the opposite side of the passage block 73 as a determination image 50. The second side surface 73b of the passage block 73 is a plane parallel to the first side surface 73a. Therefore, the camera 35 can acquire an image of the photographed component 40 with less distortion as the determination image 50.

[0225] Therefore, according to this embodiment, the turbidity judgment device 10 can judge the state of hydraulic oil using the judgment image 50 with less deformation, thereby improving the accuracy of the judgment of the state of hydraulic oil.

[0226] -Features of the second implementation form (4)-

[0226] In the turbidity determination device 10 of this embodiment, the photographed component 40, camera 35, passage block 73, first light source 36a, and second light source 36b are arranged in a housing 71. The housing 71 is opaque. Inside the housing 71, the camera 35 acquires an image of the photographed component 40 illuminated only by the light emitted from the first light source 36a and the second light source 36b, as a determination image 50. Therefore, the camera 35 can acquire an image of the photographed component 40 without being affected by light outside the housing 71.

[0227] Therefore, according to the turbidity judgment device 10 of this embodiment, the state of hydraulic oil can be judged by the judgment image 50 that accurately reflects the state of hydraulic oil, thereby improving the accuracy of the judgment of the state of hydraulic oil.

[0228] -Features of the second implementation form (5)-

[0228] In the turbidity determination device 10 of this embodiment, the first light source 36a, the camera 35, and the second light source 36b are arranged in a row along a straight oil passage 74 inside the housing 71. The camera 35 acquires images of the photographed component 40 that have received light emitted by the first light source 36a and the second light source 36b, respectively, as the determination image 50. Therefore, the camera 35 is able to acquire images of the photographed component 40 that have received light of relatively uniform intensity, as the determination image 50.

[0229] If the intensity of the light illuminating the photographed component 40 is uniform, the camera 35 can acquire an image 50 that accurately reflects the state of the hydraulic oil. Therefore, according to the turbidity judgment device 10 of this embodiment, the state of the hydraulic oil can be judged using the image 50 that accurately reflects the state of the hydraulic oil, thereby improving the accuracy of the judgment of the state of the hydraulic oil.

[0230] -Variation of the second embodiment-

[0230] The turbidity determination device 10 of the second embodiment described above can also be modified as follows. It should be noted that the following modifications can be appropriately combined or replaced as long as they do not impair the function of the turbidity determination device 10.

[0231] 〈First Variation〉

[0231] As shown in FIG18, in the camera unit 70 of the turbidity determination device 10 of this embodiment, the lens 35a of the camera 35 is away from the second side 73b of the passage block 73. However, the arrangement of the camera 35 and the passage block 73 in the camera unit 70 is not limited to the arrangement shown in FIG18.

[0232] For example, in the camera unit 70, the camera 35 may also be arranged such that its lens 35a contacts the second side surface 73b of the passage block 73. As shown in FIG24, a cylindrical lens hood 38 may be provided at the end of the lens 35a of the camera 35. In this case, it is preferable to arrange the camera 35 at the position where the end of the lens hood 38 (the end opposite to the lens 35a) contacts the second side surface 73b of the passage block 73.

[0233] When the lens 35a or the lens shield 38 is in contact with the second side surface 73b of the passage block 73, the light reflected from the second side surface 73b of the passage block 73 will not enter the camera 35. Therefore, the camera 35 can acquire an image of the photographed component 40 without being affected by the light reflected from the second side surface 73b of the passage block 73. Therefore, according to the turbidity judgment device 10 of this modified example, the state of the hydraulic oil can be judged using the judgment image 50 that accurately reflects the state of the hydraulic oil, thereby improving the accuracy of the judgment of the state of the hydraulic oil.

[0234] 〈Second Variation〉

[0234] In the turbidity judgment device 10 of this embodiment, the judgment pattern 46 drawn on the photographed component 40 is not limited to the grid-like pattern shown in FIG21.

[0235] For example, the judgment figure 46 can be the figure shown in FIG25 or FIG26. The judgment figure 46 shown in FIG25 and FIG26 consists of a rectangular frame and a plurality of parallel horizontal lines. In these judgment figures 46, the plurality of horizontal lines are arranged at certain intervals. In the judgment figure 46 shown in FIG25, the plurality of horizontal lines are substantially parallel to the short side of the frame. In the judgment figure 46 shown in FIG26, the plurality of horizontal lines are inclined relative to the short side of the frame.

[0236] 〈Third Variation Example〉

[0236] As shown in FIG27, in the turbidity judgment device 10 of this embodiment, the judgment unit 25 and the display unit 21 may also be provided in the camera unit 70. In the turbidity judgment device 10 of this modified example, the judgment unit 25 is arranged in the internal space of the housing 71, the display unit 21 is arranged on the outer surface of the housing 71, and the judgment unit 80 is omitted.

[0237] 〈Fourth Variation Example〉

[0237] The turbidity determination device 10 of this embodiment can be configured to display the determination results obtained by the determination unit 25 in the turbidity determination and cause determination operations on an external device such as a smartphone. In this case, the turbidity determination device 10 is configured to be able to wirelessly communicate with an external device such as a smartphone.

[0238] 〈Fifth Variation Example〉

[0238] In FIG16, the camera unit 70 of the turbidity determination device 10 is mounted on the return pipe 63 with the first connector member 75a above and the second connector member 75b below. However, the posture of the camera unit 70 in the state of being mounted on the return pipe 63 is not limited to the posture shown in FIG16. For example, the posture of the camera unit 70 may be such that the extending directions of the first connector member 75a and the second connector member 75b are approximately horizontal, or it may be such that the extending directions of the first connector member 75a and the second connector member 75b are inclined relative to the vertical direction.

[0239] Other Implementation Forms

[0239] The turbidity determination device 10 of the first and second embodiments described above can also be modified as follows. It should be noted that the following modifications can be appropriately combined or replaced as long as they do not impair the function of the turbidity determination device 10.

[0240] -First Variation Example-

[0240] In the turbidity determination device 10 of the first and second embodiments described above, the determination unit 25 can be composed of a general-purpose computer that executes an application program. In this specification, "computer" means "a machine that stores a program describing calculation steps (algorithms) and performs calculations according to the stored program." Therefore, "computer" in this specification includes mainframe computers, personal computers, tablet computers, smartphones, etc.

[0241] FIG28 shows a turbidity judgment device 10 applying the second embodiment of this modified example. This turbidity judgment device 10 is also a turbidity judgment system 15. In the turbidity judgment device 10 shown in FIG28, the judgment unit 80 is omitted, and the smartphone 92 constitutes the judgment unit 25.

[0242] In the turbidity determination device 10 shown in FIG28, the camera unit 70 has a communication module 91. The communication module 91 performs wireless communication based on communication standards such as Wi-Fi (registered trademark). In this modified example, the camera unit 70 transmits the determination image 50 acquired by the camera 35 to the smartphone 92 constituting the determination unit 25 via a communication line 93 such as a network.

[0243] The smartphone 92 has an application installed that enables it to function as both the judgment unit 25 and the display unit 21. As the judgment unit 25, the smartphone 92 determines the state of the hydraulic oil based on the judgment image 50 and displays the result on the smartphone 92's display. In this modified example, the smartphone 92's display constitutes the display unit 21.

[0244] -Second Variation Example-

[0244] In the turbidity determination device 10 of the first and second embodiments described above, the determination unit 25 may be configured to determine the state of hydraulic oil by means of so-called machine learning.

[0245] In the turbidity judgment device 10 of this modified example, the learned model is recorded in the memory device 27 of the judgment unit 25. This learning model is generated by machine learning, using multiple judgment images 50 with hydraulic oil in various states as objects as input data, and using the hydraulic oil state corresponding to each judgment image 50 as teacher data.

[0246] In this modified example, the judgment unit 25 inputs the judgment image 50 acquired by the camera 35 into the learned model to determine whether the turbidity of the hydraulic oil is "actually none", "low" or "high". If the turbidity of the hydraulic oil is "high", it determines whether the cause of the turbidity of the hydraulic oil is "mixing in water" or "mixing in solid matter".

[0247] The above describes the embodiments and variations, but various changes in form or detail may be made without departing from the spirit and scope of the claims. Elements related to the above embodiments, variations, and other implementation methods may also be appropriately combined or replaced. The terms "first" and "second" in the specification and claims are used to distinguish these terms and do not limit the number or order of the terms.

[0247] -Industrial availability-

[0248] As described above, this disclosure is useful for a turbidity determination device and a turbidity determination system for determining the degree of turbidity of hydraulic oil.

Claims

1. A turbidity judgment device (10) for judging the turbidity of hydraulic oil in a hydraulic device, the turbidity judgment device (10) comprising a photographed component (40), a camera unit (35), and a judgment unit (25); the photographed component (40) having a bright portion (51) and a dark portion (52); the camera unit (35) being positioned away from the photographed component (40) such that hydraulic oil exists between the camera unit (35) and the photographed component (40); the camera unit (35) acquiring an image of the photographed component (40) as a judgment image (50); the judgment unit (25) judging the turbidity of hydraulic oil acquired by the camera unit (35). The turbidity judgment work is performed by judging the degree of turbidity of the hydraulic oil by comparing the tone difference between the aforementioned bright part (51) and the aforementioned dark part (52) in the aforementioned judgment image (50); the aforementioned turbidity judgment work is performed by the aforementioned judgment unit (25) by comparing the tone difference between the aforementioned bright part (51) and the aforementioned dark part (52) in the aforementioned judgment image (50) with the reference tone difference; the aforementioned reference tone difference is the tone difference between the aforementioned bright part (51) and the aforementioned dark part (52) in the aforementioned judgment image (50) acquired by the aforementioned camera unit (35) in the state where there is no turbidity of the aforementioned hydraulic oil between the aforementioned photographed component (40) and the aforementioned camera unit (35).

2. A turbidity judgment device (10) for judging the turbidity of hydraulic oil in a hydraulic device, the turbidity judgment device (10) comprising a photographed component (40), a camera unit (35), and a judgment unit (25); the photographed component (40) has a bright part (51) and a dark part (52); the camera unit (35) is positioned away from the photographed component (40) so that there is hydraulic oil between the camera unit (35) and the photographed component (40); the camera unit (35) acquires an image of the photographed component (40) as a judgment image (50); the judgment unit (25) judges the turbidity of the hydraulic oil in the judgment image (50) acquired by the camera unit (35) based on the bright part (51) and the dark part (52) in the judgment image (50) acquired by the camera unit (35). (52) The turbidity judgment work is performed to determine the turbidity of the hydraulic oil. The turbidity judgment work is performed by the judgment unit (25) by comparing the turbidity of the bright part (51) and the dark part (52) in the judgment image (50) with the reference turbidity. The judgment unit (25) performs a color judgment work to determine the color of the hydraulic oil based on the judgment image (50). In the turbidity judgment work, the judgment unit (25) compares the reference turbidity corresponding to the color of the hydraulic oil that has been determined in the color judgment work with the turbidity of the bright part (51) and the dark part (52) in the judgment image (50).

3. The turbidity determination device described in claim 2, wherein the portion of the aforementioned determination image (50) that includes only the aforementioned bright portion (51) is the first region (56); the aforementioned color determination operation is the operation of the aforementioned determination unit (25) determining the color of the aforementioned hydraulic oil based on the aforementioned first region (56) of the aforementioned determination image (50).

4. A turbidity judgment device (10) for judging the turbidity of hydraulic oil in a hydraulic device, the turbidity judgment device (10) comprising a photographed component (40), a camera unit (35), and a judgment unit (25); the photographed component (40) has a bright part (51) and a dark part (52); the camera unit (35) is positioned away from the photographed component (40) so that there is hydraulic oil between the camera unit (35) and the photographed component (40), the camera unit (35) acquires an image of the photographed component (40) as a judgment image (50); the judgment unit (25) judges the turbidity of the hydraulic oil acquired by the camera unit (35) based on the image acquired by the camera unit (35). The turbidity judgment work is performed to determine the degree of turbidity of the hydraulic oil by using the tone difference between the aforementioned bright part (51) and the aforementioned dark part (52) in the judgment image (50); the aforementioned photographed component (40) forms a plurality of the aforementioned bright parts (51) and a plurality of the aforementioned dark parts (52); the area in the aforementioned judgment image (50) that includes the plurality of the aforementioned bright parts (51) and the plurality of the aforementioned dark parts (52) is a second region (57); in the aforementioned turbidity judgment work, the aforementioned judgment unit (25) determines the degree of turbidity of the hydraulic oil based on the difference between the maximum value of the tone value of the aforementioned bright part (51) and the minimum value of the tone value of the aforementioned dark part (52) in the aforementioned second region (57).

5. A turbidity judgment device (10) for judging the turbidity of hydraulic oil in a hydraulic device, the turbidity judgment device (10) includes a photographed component (40), a camera (35) and a judgment unit (25); the photographed component (40) forms a bright part (51) and a dark part (52); the camera (35) is disposed at a position away from the photographed component (40) so that there is hydraulic oil between the camera (35) and the photographed component (40); the camera (35) acquires an image of the photographed component (40) as a judgment image (50); the judgment unit (25) performs a turbidity judgment operation based on the tone difference between the bright part (51) and the dark part (52) in the judgment image (50) acquired by the camera (35) to judge the degree of turbidity of the hydraulic oil; the judgment unit (25) performs a cause judgment operation to judge the cause of the turbidity of the hydraulic oil.

6. The turbidity determination device as described in claim 5, wherein the area in the aforementioned determination image (50) that includes both the aforementioned bright part (51) and the aforementioned dark part (52) is a second region (57); the aforementioned cause determination work is the work of the aforementioned determination unit (25) determining the cause of the aforementioned hydraulic oil turbidity based on the average value of the tone value of the aforementioned second region (57) of the aforementioned determination image (50).

7. The turbidity determination device as described in claim 6, wherein the aforementioned photographed component (40) forms a plurality of the aforementioned bright areas (51) and a plurality of the aforementioned dark areas (52); the aforementioned second region (57) is the region in the aforementioned determination image (50) that includes the plurality of the aforementioned bright areas (51) and the plurality of the aforementioned dark areas (52).

8. The turbidity determination device as described in claim 6, wherein the aforementioned cause determination work is the work of the aforementioned determination unit (25) to determine the cause of the aforementioned hydraulic oil turbidity by comparing the average value of the pitch value of the aforementioned second region (57) of the aforementioned determination image (50) with the reference pitch value.

9. The turbidity determination device as described in claim 8, wherein the aforementioned reference tone value is the tone value of the aforementioned bright part (51) in the aforementioned determination image (50) acquired by the aforementioned camera unit (35) under the condition that there is the aforementioned hydraulic oil in a turbid state between the aforementioned photographed component (40) and the aforementioned camera unit (35).

10. The turbidity determination device as described in claim 8, wherein in the aforementioned cause determination work, when the average value of the pitch value of the second region (57) of the aforementioned determination image (50) is higher than the aforementioned reference pitch value, the aforementioned determination unit (25) determines that the cause of the turbidity of the aforementioned hydraulic oil is water mixed into the aforementioned hydraulic oil.

11. The turbidity determination device as described in claim 8, wherein in the aforementioned cause determination work, when the average value of the pitch value of the second region of the aforementioned determination image (50) is lower than the aforementioned reference pitch value, the aforementioned determination unit (25) determines that the cause of the turbidity of the aforementioned hydraulic oil is that solid matter has been mixed into the aforementioned hydraulic oil.

12. A turbidity judgment device (10) for judging the turbidity of hydraulic oil in a hydraulic device, the turbidity judgment device (10) comprising a photographed component (40), a camera unit (35), and a judgment unit (25); the photographed component (40) having a bright portion (51) and a dark portion (52); the camera unit (35) being disposed at a position away from the photographed component (40) such that there is hydraulic oil between the camera unit (35) and the photographed component (40), and the camera unit (35) acquiring an image of the photographed component (40). As a judgment image (50); the aforementioned judgment unit (25) performs a turbidity judgment operation based on the tone difference between the aforementioned bright part (51) and the aforementioned dark part (52) in the aforementioned judgment image (50) acquired by the aforementioned camera unit (35); a through hole (43) is formed on the aforementioned photographed component (40) on the surface opposite to the aforementioned camera unit (35); the aforementioned bright part (51) is formed in the portion of the aforementioned photographed component (40) other than the aforementioned through hole (43), and the aforementioned dark part (52) is formed in the aforementioned through hole (43).

13. The turbidity determination device as described in claim 12, wherein a plurality of the aforementioned through holes (43) are formed on the aforementioned photographed component (40).

14. The turbidity determination device as described in claim 12, wherein the photographed component (40) is white.

15. A turbidity judgment device (10) for judging the turbidity of hydraulic oil in a hydraulic device, the turbidity judgment device (10) comprising a photographed component (40), a camera unit (35), and a judgment unit (25); the photographed component (40) has a bright part (51) and a dark part (52); the camera unit (35) is disposed at a position away from the photographed component (40) so that there is hydraulic oil between the camera unit (35) and the photographed component (40), and the camera unit (35) acquires the turbidity of the photographed component. The image of (40) is used as the judgment image (50); the judgment unit (25) performs a turbidity judgment operation based on the tone difference between the bright part (51) and the dark part (52) in the judgment image (50) acquired by the camera unit (35) to determine the degree of turbidity of the hydraulic oil; the photographed part (40) is fixed relative to the camera unit (35); the turbidity judgment device also includes a mesh-like partition member (31) that surrounds the space (32) between the photographed part (40) and the camera unit (35).

16. A turbidity judgment device (10) for judging the turbidity of hydraulic oil in a hydraulic device, the turbidity judgment device (10) comprising a photographed component (40), a camera unit (35), and a judgment unit (25); the photographed component (40) has a bright part (51) and a dark part (52); the camera unit (35) is disposed at a position away from the photographed component (40) so that there is hydraulic oil between the camera unit (35) and the photographed component (40), the camera unit (35) acquiring the turbidity of the photographed component (40) The image of 0) is used as the judgment image (50); the judgment unit (25) performs a turbidity judgment work to judge the degree of turbidity of the hydraulic oil based on the tone difference between the bright part (51) and the dark part (52) in the judgment image (50) obtained by the camera unit (35); the turbidity judgment device also includes an intermediate component (73), which is arranged between the photographed part (40) and the camera unit (35), is made of transparent material, and has an oil passage (74) for the hydraulic oil to flow inside.

17. The turbidity determination device as described in claim 16, wherein the aforementioned intermediate component (73) has a first side surface (73a) and a second side surface (73b); the aforementioned first side surface (73a) and the aforementioned second side surface (73b) are respectively planar; the aforementioned first side surface (73a) and the aforementioned second side surface (73b) are parallel to each other; in the aforementioned intermediate component (73), the aforementioned oil passage (74) is arranged between the aforementioned first side surface (73a) and the aforementioned second side surface (73b); the aforementioned photographed component (40) is arranged to contact the aforementioned first side surface (73a) of the aforementioned intermediate component (73); the aforementioned camera unit (35) is arranged at a position opposite to the aforementioned second side surface (73b) of the aforementioned intermediate component (73).

18. The turbidity determination device as described in claim 16, comprising a first connector (75a) and a second connector (75b), wherein the first connector (75a) is connected to one end of the aforementioned oil passage (74) and is connected to an oil pipe (63) for supplying the aforementioned hydraulic oil; and the second connector (75b) is connected to the other end of the aforementioned oil passage (74) and is connected to the aforementioned oil pipe (63).

19. The turbidity determination device as described in claim 16, including a housing (71) that houses the aforementioned photographed component (40), the aforementioned camera unit (35), and the aforementioned intermediate component (73).

20. The turbidity determination device as described in claim 19, including a light source (36) housed in the aforementioned housing (71) and emitting light; the aforementioned housing (71) is made of an opaque material.

21. The turbidity determination device as described in claim 20, wherein the oil passage (74) of the aforementioned intermediate component (73) is a straight passage; the aforementioned light source (36) includes a first light source (36a) and a second light source (36b); the aforementioned first light source (36a), the aforementioned camera unit (35) and the aforementioned second light source (36b) are arranged in a row along the extension direction of the aforementioned oil passage (74).

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