Turbidity determination device

Abstract

To provide an easy-to-use turbidity determination device for determining the turbidity of hydraulic oil.SOLUTION: A turbidity determination device (10) for determining the turbidity of hydraulic oil includes an imaging target member (40), an imaging unit (35), and a determination unit (25). The imaging target member (40) forms a bright part and a dark part. The imaging unit (35) is provided distant from the imaging target member (40) so that hydraulic oil is located between the imaging unit and the imaging target member (40). The imaging unit (35) acquires an image of the imaging target member (40) as a determination image. The determination unit (25) determines the degree of the turbidity of the hydraulic oil on the basis of the gradation difference between the bright part and the dark part in the determination image.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a turbidity determination device and a turbidity determination system for determining the degree of turbidity of hydraulic oil.

Background Art

[0002] For example, hydraulic oil is used to operate hydraulic equipment such as hydraulic cylinders provided in machine tools. The hydraulic oil gradually deteriorates due to the entry of foreign substances, oxidation, etc. Conventionally, devices for determining the state of hydraulic oil have been known. Patent Document 1 discloses a device for determining the deterioration of hydraulic oil.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Many conventional devices for determining the state of hydraulic oil require collecting a sample of the hydraulic oil from the hydraulic equipment and setting it in the device, which is inconvenient to use.

[0005] An object of the present disclosure is to provide a convenient turbidity determination device for determining the turbidity of hydraulic oil.

Means for Solving the Problems

[0006] A first aspect of the present disclosure is a turbidity determination device (10) for determining the turbidity of hydraulic fluid, comprising: a member to be imaged (40) that forms a light portion (51) and a dark portion (52); an imaging unit (35) provided at a position away from the member to be imaged (40) such that the hydraulic fluid is present therebetween, and acquiring an image of the member to be imaged (40) as a determination image (50); and a determination unit (25) that performs a turbidity determination operation for determining the degree of turbidity of the hydraulic fluid based on a gradation difference between the light portion (51) and the dark portion (52) in the determination image (50) acquired by the imaging unit (35).

[0007] In the first aspect, the imaging unit (35) acquires an image of the member to be imaged (40) as the determination image (50). There is hydraulic fluid to be subjected to turbidity determination between the imaging unit (35) and the member to be imaged (40). The gradation difference between the light portion (51) and the dark portion (52) in the determination image (50) varies depending on the degree of turbidity of the hydraulic fluid present between the imaging unit (35) and the member to be imaged (40). Therefore, the determination unit (25) determines the degree of turbidity of the hydraulic fluid based on the gradation difference between the light portion (51) and the dark portion (52) in the determination image (50).

[0008] The turbidity determination device (10) according to the first aspect can determine the degree of turbidity of the hydraulic fluid if the hydraulic fluid to be subjected to turbidity determination is present between the imaging unit (35) and the member to be imaged (40). Therefore, by using this turbidity determination device (10), it is possible to determine the degree of turbidity of the hydraulic fluid without collecting a sample of the hydraulic fluid from the hydraulic equipment.

[0009] A second aspect of the present disclosure is, in the first aspect, in the turbidity determination operation, the determination unit (25) determines that the higher the degree of turbidity of the hydraulic fluid, the smaller the gradation difference between the light portion (51) and the dark portion (52) in the determination image (50).

[0010] As the degree of turbidity of the hydraulic fluid increases, the gradation difference between the light portion (51) and the dark portion (52) in the determination image (50) decreases. Utilizing this, the determination unit (25) according to the second aspect determines the degree of turbidity of the hydraulic fluid.

[0011] In a third aspect of the present disclosure, in the first or second aspect, the turbidity determination operation is an operation in which the determination unit (25) determines the degree of turbidity of the hydraulic oil by comparing the gradation difference between the bright part (51) and the dark part (52) in the determination image (50) with a reference gradation difference.

[0012] In the third aspect, the determination unit (25) determines the degree of turbidity of the hydraulic oil by comparing the gradation difference between the bright part (51) and the dark part (52) in the determination image (50) with a reference gradation difference.

[0013] In a fourth aspect of the present disclosure, in the third aspect, the reference gradation difference is the gradation difference between the bright part (51) and the dark part (52) in the determination image (50) acquired by the imaging unit (35) when the hydraulic oil in a non-turbid state exists between the member to be imaged (40) and the imaging unit (35).

[0014] In the fourth aspect, the determination unit (25) uses, as the reference gradation difference, the gradation difference between the bright part (51) and the dark part (52) when the hydraulic oil existing between the member to be imaged (40) and the imaging unit (35) is in a non-turbid state.

[0015] In a fifth aspect of the present disclosure, in the third or fourth aspect, the determination unit (25) performs a color determination operation for determining the color of the hydraulic oil based on the determination image (50), and in the turbidity determination operation, compares the reference gradation difference corresponding to the color of the hydraulic oil determined in the color determination operation with the gradation difference between the bright part (51) and the dark part (52) in the determination image (50).

[0016] The determination unit (25) in the fifth aspect determines the color of the hydraulic oil in the color determination operation. In the turbidity determination operation, the determination unit (25) compares the reference gradation difference corresponding to the color of the hydraulic oil with the gradation difference between the bright part (51) and the dark part (52) in the determination image (50) acquired by the imaging unit (35). Therefore, even when the color of the hydraulic oil changes during use of the hydraulic oil, the determination unit (25) can appropriately determine the degree of turbidity of the hydraulic oil.

[0017] In a sixth aspect of the present disclosure, in the fifth aspect described above, a portion of the determination image (50) that includes only the light portion (51) is the first region (56), and the color determination operation is an operation in which the determination unit (25) determines the color of the hydraulic oil based on the first region (56) of the determination image (50).

[0018] In the sixth aspect, the determination unit (25) determines the color of the hydraulic oil based on the first region (56) that is a part of the determination image (50) and includes only the light portion (51).

[0019] In a seventh aspect of the present disclosure, in any one of the first to sixth aspects described above, the member to be imaged (40) forms a plurality of the light portions (51) and a plurality of the dark portions (52), and a region of the determination image (50) that includes a plurality of the light portions (51) and a plurality of the dark portions (52) is the second region (57). In the turbidity determination operation, the determination unit (25) determines the degree of turbidity of the hydraulic oil based on the difference between the maximum value of the gradation value of the light portion (51) and the minimum value of the gradation value of the dark portion (52) in the second region (57).

[0020] In the seventh aspect, the second region (57) of the determination image (50) includes a plurality of the light portions (51) and a plurality of the dark portions (52). The determination unit (25) determines the degree of turbidity of the hydraulic oil based on the difference between the "maximum value of the gradation value of the light portion (51)" and the "minimum value of the gradation value of the dark portion (52)" in the second region (57).

[0021] In an eighth aspect of the present disclosure, in any one of the first to sixth aspects described above, the determination unit (25) performs a cause determination operation for determining the cause of the turbidity of the hydraulic oil.

[0022] In the eighth aspect, the determination unit (25) determines the cause of the turbidity of the hydraulic oil.

[0023] In a ninth aspect of the present disclosure, in the eighth aspect described above, a region including both the bright part (51) and the dark part (52) of the determination image (50) is a second region (57), and the cause determination operation is an operation in which the determination unit (25) determines the cause of the turbidity of the hydraulic oil based on the average value of the gradation values in the second region (57) of the determination image (50).

[0024] In the ninth aspect, the second region (57) of the determination image (50) includes both the bright part (51) and the dark part (52). In the cause determination operation, the determination unit (25) determines the cause of the turbidity of the hydraulic oil based on the average value of the gradation values in the second region (57).

[0025] In a tenth aspect of the present disclosure, in the ninth aspect described above, the member to be imaged (40) forms a plurality of the bright parts (51) and a plurality of the dark parts (52), and the second region (57) is a region of the determination image (50) that includes a plurality of the bright parts (51) and a plurality of the dark parts (52).

[0026] In the tenth aspect, the second region (57) of the determination image (50) includes a plurality of the bright parts (51) and a plurality of the dark parts (52).

[0027] In an eleventh aspect of the present disclosure, in the ninth or tenth aspect described above, the cause determination operation is an operation in which the determination unit (25) determines the cause of the turbidity of the hydraulic oil by comparing the average of the gradation values in the second region (57) of the determination image (50) with a reference gradation value.

[0028] In the cause determination operation of the eleventh aspect, the determination unit (25) determines the cause of the turbidity of the hydraulic oil by comparing the average value of the gradation values in the second region (57) of the determination image (50) with a reference gradation value.

[0029] A twelfth aspect of the present disclosure is that, in the eleventh aspect, the reference gradation value is the gradation value of the bright part (51) in the determination image (50) acquired by the imaging unit (35) with the hydraulic oil in a non-turbid state existing between the member to be imaged (40) and the imaging unit (35).

[0030] In a twelfth aspect, the determination unit (25) uses, as the reference gradation value, the gradation value of the bright part (51) when the hydraulic oil existing between the member to be imaged (40) and the imaging unit (35) is in a non-turbid state.

[0031] A thirteenth aspect of the present disclosure is that, in the eleventh or twelfth aspect, in the cause determination operation, the determination unit (25) determines that the cause of the turbidity of the hydraulic oil is the mixing of water into the hydraulic oil when the average value of the gradation values in the second region (57) of the determination image (50) is higher than the reference gradation value.

[0032] The determination unit (25) of the thirteenth aspect determines that the cause of the turbidity of the hydraulic oil is the mixing of water into the hydraulic oil when the average value of the gradation values in the second region (57) of the determination image (50) is closer to the "white" gradation value than the reference gradation value in the cause determination operation.

[0033] A fourteenth aspect of the present disclosure is that, in any one of the eleventh to thirteenth aspects, in the cause determination operation, the determination unit (25) determines that the cause of the turbidity of the hydraulic oil is the mixing of solids into the hydraulic oil when the average value of the gradation values in the second region of the determination image (50) is lower than the reference gradation value.

[0034] The determination unit (25) of the fourteenth aspect determines that the cause of the turbidity of the hydraulic oil is the mixing of solids (for example, particles such as sludge) into the hydraulic oil when the average value of the gradation values in the second region (57) of the determination image (50) is closer to the "black" gradation value than the reference gradation value in the cause determination operation.

[0035] According to the 15th aspect of the present disclosure, in any one of the 1st to 14th aspects, a through hole (43) that opens to a surface facing the imaging unit (35) is formed in the object member (40) to be imaged. A portion of the object member (40) other than the through hole (43) forms the bright portion (51), and the through hole (43) forms the dark portion (52).

[0036] In the object member (40) according to the 15th aspect, a through hole (43) is formed. A portion of the object member (40) other than the through hole (43) reflects light, so it forms the bright portion (51). The through hole (43) of the object member (40) does not reflect light, so it forms the dark portion (52).

[0037] According to the 16th aspect of the present disclosure, in the 15th aspect, a plurality of through holes (43) are formed in the object member (40).

[0038] In the object member (40) according to the 16th aspect, a plurality of through holes (43) are formed. Therefore, the object member (40) forms a plurality of bright portions (51) and a plurality of dark portions (52).

[0039] According to the 17th aspect of the present disclosure, in the 15th or 16th aspect, the object member (40) is white.

[0040] In the 17th aspect, the white object member (40) forms the bright portion (51).

[0041] According to the 18th aspect of the present disclosure, in any one of the 1st to 18th aspects, the object member (40) is fixed to the imaging unit (35).

[0042] In the 18th aspect, the distance between the object member (40) and the imaging unit (35) is kept constant.

[0043] According to the 19th aspect of the present disclosure, in the 18th aspect, a net-like partition member (31) that surrounds the space (32) between the object member (40) and the imaging unit (35) is provided.

[0044] In the 19th aspect, the space (32) between the member to be imaged (40) and the imaging unit (35) is surrounded by a partition member (31). The partition member (31) is in a net shape. Therefore, while allowing the inflow of hydraulic oil into the space (32) between the member to be imaged (40) and the imaging unit (35), the partition member (31) can suppress the intrusion of foreign matter into the space (32) between the member to be imaged (40) and the imaging unit (35).

[0045] In the 20th aspect of the present disclosure, in the above 1st to 14th aspects, an intermediate member (73) is provided between the member to be imaged (40) and the imaging unit (35), made of a transparent material, and having an oil passage (74) formed therein for flowing hydraulic oil.

[0046] In the 20th aspect, the intermediate member (73) is provided between the member to be imaged (40) and the imaging unit (35). When the hydraulic oil is flowing through the oil passage (74) of the intermediate member (73), there is hydraulic oil to be the object of turbidity determination between the imaging unit (35) and the member to be imaged (40). In this state, the imaging unit (35) acquires an image of the member to be imaged (40) as a determination image (50).

[0047] In the 20th aspect, the hydraulic oil to be the object of turbidity determination flows through the oil passage (74) formed inside the intermediate member (73). In this aspect, the hydraulic oil does not come into contact with the member to be imaged (40) and the imaging unit (35). Therefore, foreign matter contained in the hydraulic oil does not adhere to the member to be imaged (40) and the imaging unit (35).

[0048] The 21st aspect of the present disclosure is that in the 20th aspect described above, the intermediate member (73) has a first side surface (73a) and a second side surface (73b), each of the first side surface (73a) and the second side surface (73b) is a flat surface, the first side surface (73a) and the second side surface (73b) are parallel to each other, in the intermediate member (73), the oil passage (74) is arranged between the first side surface (73a) and the second side surface (73b), the member to be imaged (40) is provided in contact with the first side surface (73a) of the intermediate member (73), and the imaging unit (35) is provided at a position facing the second side surface (73b) of the intermediate member (73).

[0049] In the 21st aspect, the first side surface (73a) of the intermediate member (73) with which the member to be imaged (40) is in contact is a flat surface. The imaging unit (35) faces the second side surface (73b) of the intermediate member (73) and acquires an image of the member to be imaged (40) arranged on the other side of the intermediate member (73) as a determination image (50). The second side surface (73b) of the intermediate member (73) is a flat surface parallel to the first side surface (73a). Therefore, the imaging unit (35) can acquire an image of the member to be imaged (40) with relatively little distortion as the determination image (50).

[0050] The 22nd aspect of the present disclosure is that in the 20th or 21st aspect described above, it includes a first joint member (75a) that communicates with one end of the oil passage (74) and is connected to an oil pipe (63) through which the hydraulic oil flows, and a second joint member (75b) that communicates with the other end of the oil passage (74) and is connected to the oil pipe (63).

[0051] In the 22nd aspect, the oil passage (74) formed in the intermediate member (73) communicates with the oil pipe (63) via the first joint member (75a) and the second joint member (75b). Therefore, the hydraulic oil flowing through the oil pipe (63) passes through the oil passage (74) of the intermediate member (73).

[0052] A 23rd aspect of the present disclosure includes, in any one of the 20th to 22nd aspects, a case (71) that houses the photographed member (40), the imaging unit (35), and the intermediate member (73).

[0053] In the 23rd aspect, the photographed member (40), the imaging unit (35), and the intermediate member (73) are arranged in the case (71).

[0054] A 24th aspect of the present disclosure includes, in the 23rd aspect, a light source (36) that is housed in the case (71) and emits light, and the case (71) is made of a material that does not transmit light.

[0055] In the 24th aspect, the photographed member (40), the imaging unit (35), the intermediate member (73), and the light source (36) are arranged inside the case (71). The case (71) does not transmit light. Inside the case (71), the imaging unit (35) acquires an image of the photographed member (40) that has received only the light emitted by the light source (36) as a determination image (50). Therefore, the imaging unit (35) can acquire an image of the photographed member (40) without being affected by the light outside the case (71).

[0056] A 25th aspect of the present disclosure includes, in the 24th aspect, the oil passage (74) of the intermediate member (73) is a linear passage, the light source (36) includes a first light source (36a) and a second light source (36b), and the first light source (36a), the imaging unit (35), and the second light source (36b) are arranged in a line in order along the extension direction of the oil passage (74).

[0057] In the 25th aspect, the imaging unit (35) acquires an image of the photographed member (40) that has received the light emitted by each of the first light source (36a) and the second light source (36b). In this aspect, the first light source (36a), the imaging unit (35), and the second light source (36b) are arranged in a line along the linear oil passage (74). Therefore, the imaging unit (35) can acquire an image of the photographed member (40) that has received light with relatively uniform intensity.

[0058] The 26th aspect of the present disclosure is a turbidity determination system (15) for determining the turbidity of hydraulic fluid, comprising a member to be imaged (40) that forms a bright portion (51) and a dark portion (52), an imaging unit (35) provided at a position away from the member to be imaged (40) such that the hydraulic fluid is present therebetween, and configured to acquire an image of the member to be imaged (40) as a determination image (50), and a determination unit (25) configured to perform a turbidity determination operation for determining the degree of turbidity of the hydraulic fluid based on the gradation difference between the bright portion (51) and the dark portion (52) in the determination image (50) acquired by the imaging unit (35).

[0059] In the 26th aspect, the imaging unit (35) acquires an image of the member to be imaged (40) as the determination image (50). There is hydraulic fluid to be subject to turbidity determination between the imaging unit (35) and the member to be imaged (40). The gradation difference between the bright portion (51) and the dark portion (52) in the determination image (50) varies depending on the degree of turbidity of the hydraulic fluid between the imaging unit (35) and the member to be imaged (40). Therefore, the determination unit (25) determines the degree of turbidity of the hydraulic fluid based on the gradation difference between the bright portion (51) and the dark portion (52) in the determination image (50).

[0060] The turbidity determination system (15) according to the 26th aspect can determine the degree of turbidity of the hydraulic fluid if the hydraulic fluid to be subject to turbidity determination is present between the imaging unit (35) and the member to be imaged (40). Therefore, by using this turbidity determination device (10), it is possible to determine the degree of turbidity of the hydraulic fluid without collecting a sample of the hydraulic fluid from the hydraulic equipment.

Brief Description of the Drawings

[0061]

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DETAILED DESCRIPTION OF THE INVENTION

[0062] 《Embodiment 1》 Embodiment 1 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 provided in a hydraulic oil tank (60) that constitutes a hydraulic circuit.

[0063] -Hydraulic oil tank- The hydraulic oil tank (60) in which the turbidity determination device (10) of this embodiment is provided will be described with reference to FIG. 1.

[0064] The hydraulic oil tank (60) includes a tank body (61), a delivery 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 equipment such as hydraulic cylinders.

[0065] The tank body (61) is a rectangular parallelepiped container. The delivery pipe (62) is a pipe connecting the tank body (61) to a hydraulic pump. The inlet end of the delivery pipe (62) communicates with the internal space of the tank body (61). The filter (64) is connected to the inlet end of the delivery pipe (62). The filter (64) collects solid matter such as sludge contained in the hydraulic oil flowing into the delivery pipe (62). The return pipe (63) is a pipe for introducing the 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] -Configuration of turbidity determination device- As shown in FIG. 2, the turbidity determination device (10) includes a main body unit (20), a sheath tube (30), a camera (35), a partition member (31), a member to be photographed (40), and a determination unit (25).

[0067] 〈Main body unit〉 The main body unit (20) is a rectangular parallelepiped box-shaped member. Inside the main body unit (20), the determination unit (25) is accommodated. On the upper surface of the main body unit (20), a display unit (21) is provided. This display unit (21) is one or more LED (Light Emitting Diode) lamps.

[0068] 〈Sheath tube〉 The sheath tube (30) is a circular tube made of metal or resin. The proximal end of the sheath tube (30) is connected to the lower surface of the main body unit (20).

[0069] 〈Camera〉 As also shown in FIG. 3, the camera (35) is formed in a small cylindrical shape. The camera (35) is provided inside the sheath tube (30). The tip of the camera (35) protrudes to the outside from the tip of the sheath tube (30). The camera (35) acquires a color image. The camera (35) is an imaging unit that acquires an image of the member to be photographed (40).

[0070] The camera (35) is provided with a light source (36). The light source (36) is a white LED lamp. The light source (36) is disposed near the tip of the camera (35) and irradiates light forward from the tip of the camera (35). The connection cable (37) of the camera (35) is electrically connected to the determination unit (25) within the main body unit (20). The camera (35) sends an image signal to the determination unit (25) through the connection cable (37).

[0071] 〈Partition member〉 The partition member (31) is a cylindrical wire mesh. The proximal end of the partition member (31) is attached to the tip of the sheath tube (30). The partition member (31) extends forward (downward in FIG. 2) from the tip of the sheath tube (30). The diameter of the partition member (31) is equal to or greater than the diameter of the sheath tube (30).

[0072] The space inside the partition member (31) is the determination space (32). The determination space (32) is surrounded by the partition member (31) which is a cylindrical wire mesh.

[0073] 〈Member to be photographed〉 The member to be photographed (40) is a member formed in a thick disk shape as a whole. The diameter of the member to be photographed (40) is, for example, about 13 mm. The material of the member to be photographed (40) is a white resin.

[0074] As shown in FIG. 3, the member to be photographed (40) is provided so as to close the tip of the partition member (31). The member to be photographed (40) is fixed to the camera (35) via the partition member (31) and the sheath tube (30). The member to be photographed (40) is immovable relative to the camera (35). Therefore, the distance L from the camera (35) to the member to be photographed (40) is kept constant.

[0075] As shown in FIGS. 4 and 5, the member to be imaged (40) includes a single ring portion (41) and two bridge portions (42). The ring portion (41) is a ring-shaped portion along the outer edge of the member to be imaged (40). Each bridge portion (42) is a straight rod-shaped portion that traverses the space inside the ring portion (41). The ring portion (41) and each bridge portion (42) are integrally formed.

[0076] In the member to be imaged (40), the two bridge portions (42) are arranged substantially parallel to each other with a gap therebetween. The space inside the ring portion (41) is divided into three portions by the two bridge portions (42). The three spaces divided by the two bridge portions (42) are through holes (43) that each penetrate the member to be imaged (40) in the thickness direction.

[0077] <Determination unit> As shown in FIG. 6, the determination unit (25) includes a CPU (26) mounted on a substrate and a memory device (27) that stores a program for operating the CPU (26). The memory device (27) is a semiconductor memory.

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

[0079] - Installation state of the turbidity determination device - As shown in FIG. 1, the turbidity determination device (10) is provided in the hydraulic oil tank (60). The turbidity determination device (10) is attached to the tank body (61) of the hydraulic oil tank (60) in a posture where the sheath tube (30) extends downward from the main body unit (20).

[0080] The main unit (20) of the turbidity determination device (10) is located outside the tank body (61). The sheath tube (30) of the turbidity determination device (10) penetrates the top plate of the tank body (61) and is inserted into the internal space of the tank body (61). The sheath tube (30) of the turbidity determination device (10) is inserted, for example, into the spare port of the hydraulic oil tank (60). The spare port is a member for attaching an additional return pipe (63) to the hydraulic oil tank (60).

[0081] In a state where the turbidity determination device (10) is installed in the hydraulic oil tank (60), the tip of the sheath tube (30) incorporating the camera (35), the partition member (31) fixed to the tip of the sheath tube (30), and the member to be imaged (40) are located below the oil level (65) in the tank body (61). In other words, the tip of the sheath tube (30), the partition member (31), and the member to be imaged (40) are immersed in the hydraulic oil stored in the hydraulic oil tank (60).

[0082] The hydraulic oil in the tank body (61) flows into the determination space (32) formed between the camera (35) and the member to be imaged (40) through the mesh-like partition member (31). Therefore, the determination space (32) is filled with the hydraulic oil stored in the hydraulic oil tank (60).

[0083] -Operation of the turbidity determination device- The operation of the turbidity determination device (10) will be described.

[0084] In the turbidity determination device (10), the camera (35) as the imaging unit acquires an image of the member to be imaged (40) as the determination image (50). Further, in the turbidity determination device (10), the determination unit (25) performs a color determination operation, a turbidity determination operation, and a cause determination operation based on the determination image (50). The determination unit (25) performs the color determination operation and the turbidity determination operation in order. Further, when the determination unit (25) determines that the degree of turbidity of the hydraulic oil is high (in other words, the state of the hydraulic oil is bad) in the turbidity determination operation, the cause determination operation is performed.

[0085] 〈Determination image〉 As described above, the camera (35) acquires an image of the member to be photographed (40) as a determination image (50). The camera (35) transmits the acquired determination image (50) to the determination unit (25). The determination unit (25) stores the determination image (50) received from the camera (35) in the memory device (27) as a color image with 256 gradations for each of R (red), G (green), and B (blue). Note that the gradations of RGB shown here are merely examples.

[0086] An example of the determination image (50) is shown in FIG. 7. The determination image (50) is an image of the plane of the member to be photographed (40).

[0087] The light emitted by the light source (36) of the camera (35) hits and reflects off the ring portion (41) and the bridge portion (42) of the member to be photographed (40). Therefore, in the determination image (50), the portions corresponding to the ring portion (41) and the bridge portion (42) of the member to be photographed (40) become bright portions (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 member to be photographed (40). Since there is a certain distance or more from the member to be photographed (40) to the bottom of the hydraulic oil tank (60), the light that has passed through the through-hole (43) of the member to be photographed (40) hardly reaches the bottom of the hydraulic oil tank (60). Therefore, in the determination image (50), the portion corresponding to the through-hole (43) of the member to be photographed (40) becomes a dark portion (52) with relatively low brightness.

[0089] Note that a partition member (31) made of a wire mesh is reflected in the region outside the ring portion (41) of the member to be photographed (40) in the determination image (50).

[0090] 〈Color determination operation〉 The color determination operation will be described. The color determination operation is "an operation in which the determination unit (25) determines the color of the hydraulic oil based on the determination image (50)".

[0091] As shown in FIG. 8, the determination unit (25) sets four first regions (56) in the determination image (50) which is a color image. The first region (56) is a part of the determination image (50) and includes only the bright part (51). Note that the number of the first regions (56) is merely an example and may be one. The determination unit (25) sets the first region (56) in a part of the determination image (50) corresponding to the ring part (41) of the member to be imaged (40). However, the determination unit (25) may set the first region (56) in a part of the determination image (50) corresponding to the bridge part (42) of the member to be imaged (40).

[0092] The determination unit (25) determines the color of the hydraulic oil based on the ASTM color. The ASTM color is a classification of the colors of petroleum products into 16 levels based on the provisions of ASTM D1500. The determination unit (25) of the present embodiment classifies the color of the hydraulic oil into four types: "transparent", "yellow", "goldenrod", and "black". One or more levels of the ASTM color correspond to each of "transparent", "yellow", "goldenrod", and "black". Note that the number of classifications of the color of the hydraulic oil is merely an example.

[0093] The memory device (27) of the determination unit (25) stores in advance, for each of "transparent", "yellow", "goldenrod", and "black", the range of the gradation values of each of RGB as a color determination reference range. The gradation value is a numerical value indicating the number of the 256 gradation levels.

[0094] The ring part (41) and the bridge part (42) of the member to be imaged (40) are white. Also, at the time when the camera (35) acquires the determination image (50), the determination space (32) between the camera (35) and the member to be imaged (40) is filled with the hydraulic oil in the hydraulic oil tank (60). Therefore, the color of the part of the determination image (50) corresponding to the ring part (41) and the bridge part (42) is substantially the same as the color of the hydraulic oil filling the determination space (32).

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

[0096] 〈Reference gradation difference〉 Although it will be described in detail later, in the turbidity determination operation, the determination unit (25) determines the degree of turbidity of the hydraulic oil using the reference gradation difference. Here, the reference gradation difference will be described.

[0097] The reference gradation difference is determined based on the determination image (50) acquired by the camera (35) when the hydraulic oil in a non-turbid state fills the determination space (32). The reference gradation difference ΔVC_r is the difference between the maximum reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n) in the second region (57) of this determination image (50) (ΔVC_r = VC_max(n) - VC_min(n)). The second region (57) will be described later. The maximum reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n) for calculating the reference gradation difference are determined in the process of designing the turbidity determination device (10) and are pre-recorded in the memory device (27) of the determination unit (25).

[0098] As shown in FIG. 9, the second region (57) is a part of the determination image (50). The second region (57) is a linear region substantially orthogonal to the bridge portion (42) of the member to be imaged (40). The second region (57) passes through the center of the ring portion (41) of the member to be imaged (40).

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

[0100] FIG. 10 shows the gradation values of the second region (57) in the determination image (50) converted into a 256 - gradation grayscale image. This determination image (50) is the determination image (50) acquired by the camera (35) in order to determine the reference gradation difference in the process of designing the turbidity determination device (10). This determination image (50) is the determination image (50) acquired by the camera (35) when the operating oil in a non - turbid state fills the determination space (32).

[0101] The above - mentioned grayscale gradations are merely examples. 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 is a value indicating which gray level it is from "0 (black)" to "255 (white)". In a grayscale, the lower the gradation value of gray, the closer it is to black, and the higher the gradation value of gray, the closer it is to white.

[0102] As shown in FIG. 10, in the second region (57), the gradation value of the light portion (51) is relatively high, and the gradation value of the dark portion (52) is relatively low. The memory device (27) of the determination unit (25) stores the maximum value of the gradation values of the light portions (51) in the second region (57) as the maximum reference gradation value VC_max(n) of the second region (57). Also, the memory device (27) of the determination unit (25) stores the minimum value of the gradation values of the dark portions (52) in the second region (57) as the minimum reference gradation value VC_min(n) of the second region (57).

[0103] Here, the maximum reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n) of the second region (57) change according to the color of the hydraulic oil. As the color of the hydraulic oil becomes darker (in other words, approaches from transparent to black), the difference between the maximum reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n) in the second region (57) gradually becomes smaller. In FIG. 10, VC_max(1) and VC_min(1) are the maximum reference gradation value and the minimum reference gradation value when the color of the hydraulic oil is "transparent (n = 1)". Also, VC_max(3) and VC_min(3) are the maximum reference gradation value and the minimum reference gradation value when the color of the hydraulic oil is "gold (n = 3)".

[0104] Therefore, for the case where the color of the hydraulic oil in a non-turbid state is respectively "transparent (n = 1)", "yellow (n = 2)", "gold (n = 3)", and "black (n = 4)", the memory device (27) of the determination unit (25) stores the maximum reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n) individually. The number of "pairs of the reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n)" stored in the memory device (27) of the determination unit (25) is the same as the number of classifications of the color of the hydraulic oil in the color determination operation.

[0105] 〈Turbidity determination operation〉 The turbidity determination operation will be described. The turbidity determination operation is "an operation in which the determination unit (25) determines the degree of turbidity of the hydraulic oil based on the determination image (50)".

[0106] In the turbidity determination operation, the determination unit (25) reads out the maximum reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n) corresponding to the color of the hydraulic oil determined in the color determination operation from the memory device (27). For example, when it is determined that the color of the hydraulic oil is "yellow (n = 2)" in the color determination operation, the determination unit (25) reads out the maximum reference gradation value VC_max(2) and the minimum reference gradation value VC_min(2) corresponding to "yellow" from the memory device (27). The determination unit (25) sets the difference between the maximum reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n) read out from the memory device (27) as the reference gradation difference ΔVC_r (ΔVC_r = VC_max(n) - VC_min(n)).

[0107] As shown in FIG. 11, the determination unit (25) divides the reference gradation difference ΔVC_r into a plurality of levels. Specifically, the determination unit (25) equally divides the reference gradation difference ΔVC_r into h levels. "h" is an integer of 2 or more. The determination unit (25) of the present embodiment equally divides the reference gradation difference ΔVC_r into 10 levels (h = 10). The determination unit (25) calculates the threshold value ΔVC_s(m) regarding the gradation difference using the following formula 1. "m" in formula 1 is an integer from 0 (zero) to h. ΔVC_s(m) = m×(ΔVC_r / h) (formula 1)

[0108] Then, the determination unit (25) sets h levels (LEVEL(m)). Each level is a numerical range represented by the following formula 2. ΔVC_s(m - 1) < LEVEL(m) ≦ ΔVC_s(m) (formula 2)

[0109] In the turbidity determination operation, the determination unit (25) converts the determination image (50) from a color image to a grayscale image. The determination unit (25) of the present embodiment converts the determination image (50) into a 256 - gradation grayscale image.

[0110] The above gray scale gradations are merely examples. In a 256 - gradation gray scale, the lowest gradation value "0" corresponds to "black", and the highest gradation value "255" corresponds to "white". The gradation value indicates which gray level it is from "0 (black)" to "255 (white)". In the gray scale, the lower the gradation value of gray, the closer it is to black, and the higher the gradation value of gray, the closer it is to white.

[0111] The determination unit (25) specifies the maximum gradation value VC1 and the minimum gradation value VC2 of the second region (57) in the determination image (50) converted into a gray - scale image. The maximum gradation value VC1 of the second region (57) is the maximum value of the gradation values of the bright part (51) in the second region (57). The minimum gradation value VC2 of the second region (57) is the minimum value of the gradation values of the dark part (52) in the second region (57). The determination unit (25) calculates the difference between the maximum gradation value VC1 and the minimum gradation value VC2 of the second region (57), and sets this value as the gradation difference ΔVC (= VC1 - VC2) between the bright part (51) and the dark part (52) in the second region (57).

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

[0113] Therefore, the determination unit (25) determines which level shown in FIG. 11 the calculated gradation difference ΔVC (= VC1 - VC2) between the bright part (51) and the dark part (52) belongs to. Then, the determination unit (25) determines which of "substantially none", "low", and "high" the degree of turbidity of the hydraulic oil corresponds to according to the level to which the gradation difference ΔVC belongs.

[0114] An example of the correspondence between these three stages and the level to which the gradation difference ΔVC belongs is shown. When the gradation difference ΔVC belongs to LEVEL(8) to LEVEL(10), the determination unit (25) determines that "the working oil is substantially free of turbidity and the working 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 working oil is low and the working 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 working oil is high and the working oil is not suitable for use".

[0115] 〈Cause determination operation〉 When the determination unit (25) determines that "the degree of turbidity of the working oil is high and the working oil is not suitable for use", it 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 working 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 in the second region (57) of the determination image (50). Also, 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. Then, the determination unit (25) determines the cause of the turbidity of the working oil by comparing the calculated average value VC_ave of the gradation values in the second region (57) with the reference gradation value.

[0117] When the working oil is turbid due to the mixing of water, as the degree of turbidity of the working oil increases, the gradation of the determination image (50) gradually approaches "white" as a whole. Therefore, the gradation of the second region (57) of the determination image (50) becomes high as a whole. Thus, when the calculated 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) determines that the cause of the turbidity of the working oil is "mixing of water".

[0118] On the other hand, 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) gradually approaches "black" as a whole. Therefore, the gradation of the second region (57) of the determination image (50) becomes lower as a whole. Thus, when the average value VC_ave of the gradation values of the calculated second region (57) is less than or equal to 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 solid matter such as sludge".

[0119] -Overall flow of the operation of the turbidity determination device- The overall flow of the operation of the turbidity determination device (10) will be described with reference to the flowchart of FIG. 12.

[0120] The determination unit (25) of the turbidity determination device (10) performs a series of processes shown in the flowchart of FIG. 12 by the CPU (26) executing the program recorded in the memory device (27). In the flowchart of FIG. 12, the process of step ST2 is a color determination operation executed by the determination unit (25), the processes from step ST3 to step ST9 are turbidity determination operations executed by the determination unit (25), and the processes from step ST10 to step ST11 are cause determination operations executed by the determination unit (25).

[0121] 〈Step ST1〉 In the process of step ST1, the camera (35) acquires the determination image (50). Specifically, in a state where the determination space (32) is filled with the hydraulic oil in the hydraulic oil tank (60), the light source (36) of the camera (35) irradiates light on the member to be photographed (40), and the camera (35) photographs the member to be photographed (40). The camera (35) transmits the acquired determination image (50) to the determination unit (25). The determination unit (25) stores the determination image (50) sent from the camera (35) in the memory device (27) as a color image with 256 gradations for each of R (red), G (green), and B (blue). When the process of step ST1 is completed, the determination unit (25) performs the process of step ST2.

[0122] <Step ST2> The process of Step ST2 is a color determination operation performed by the determination unit (25). The detailed content of the color determination operation is as described above. In the process of Step ST2, the determination unit (25) determines which of "transparent (n = 1)", "yellow (n = 2)", "gold (n = 3)", and "black (n = 4)" the color of the hydraulic oil that fills the determination space (32) corresponds to based on the four first regions (56) set in the determination image (50) which is a color image.

[0123] The color of the hydraulic oil that fills the determination 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 determination unit (25) determines the color of the hydraulic oil in the hydraulic oil tank (60). When the process of Step ST2 is completed, the determination unit (25) performs the process of Step ST3.

[0124] <Step ST3> In the process of Step ST3, the determination unit (25) starts the turbidity determination operation.

[0125] In the process of Step ST3, the determination unit (25) sets the reference gradation difference ΔVC_r. Specifically, the determination unit (25) reads out the maximum reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n) corresponding to the color of the hydraulic oil determined in the process of Step ST2 from the memory device (27). Then, the determination unit (25) sets the difference between the maximum reference gradation value VC_max(n) and the minimum reference gradation value VC_min(n) read from the memory device (27) as the reference gradation difference ΔVC_r (ΔVC_r = VC_max(n) - VC_min(n)). When the process of Step ST3 is completed, the determination unit (25) performs the process of Step ST4.

[0126] <Step ST4> In the process of step ST4, the determination unit (25) uses the reference gradation difference ΔVC_r set in the process of step ST3 and performs the arithmetic processing shown in the above formula 1 to set a plurality of (in the step embodiment, 10) levels (LEVEL(m)). When the process of step ST4 is completed, the determination unit (25) performs the process of step ST5.

[0127] 〈Step ST5〉 In the process of step ST5, the determination unit (25) converts the determination image (50), which is a color image acquired by the camera (35) in the process of step ST1, into a 256-gradation grayscale image. When the process of step ST5 is completed, the determination unit (25) performs the process of step ST6.

[0128] 〈Step ST6〉 In the process of step ST6, the determination unit (25) identifies the maximum gradation value VC1 and the minimum gradation value VC2 of the second region (57) in the determination image (50) based on the determination image (50) converted into a grayscale image in the process of step ST5. Then, the determination unit (25) calculates the difference between the maximum gradation value VC1 and the minimum gradation value VC2 of the second region (57), and sets this value as the gradation difference ΔVC (=VC1 - VC2) between the bright part (51) and the dark part (52) in the second region (57). When the process of step ST6 is completed, the determination unit (25) performs the process of step ST7.

[0129] 〈Step ST7〉 In the process of step ST7, the determination unit (25) determines whether the condition "ΔVC_s(10) < ΔVC" is satisfied. If this condition is met, it means that the gradation difference ΔVC between the bright part (51) and the dark part (52) in the second region (57) exceeds LEVEL(10). If the determination image (50) acquired by the camera (35) in the process of step ST1 is normal, the gradation difference ΔVC does not exceed LEVEL(10). Therefore, when the gradation difference ΔVC exceeds LEVEL(10), for example, there may be a problem such as the adhesion of bubbles to the member to be photographed (40), and it is highly likely that the state of the hydraulic oil cannot be appropriately determined based on the determination image (50) acquired by the camera (35) in the process of step ST1.

[0130] Therefore, when the condition "ΔVC_s(10) < ΔVC" is satisfied, the determination unit (25) performs the processes from step ST1 to step ST6 again. That is, in this case, the determination unit (25) performs a color determination operation using the determination image (50) newly acquired by the camera (35), and calculates the gradation 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 satisfied, the determination unit (25) performs the process of step ST8.

[0131] 〈Step ST8〉 In the process of step ST8, the determination unit (25) determines whether the condition "ΔVC_s(7) < ΔVC" is satisfied. If this condition is met, it means that the gradation difference ΔVC between the bright part (51) and the dark part (52) in the second region (57) belongs to the range from LEVEL(8) to LEVEL(10). When the gradation difference ΔVC belongs to the range from LEVEL(8) to LEVEL(10), it corresponds to "substantially no" turbidity of the hydraulic oil. Therefore, when this condition is satisfied, the determination unit (25) performs the process of step ST12. On the other hand, when this condition is not satisfied, the determination unit (25) performs the process of step ST9.

[0132] 〈Step ST9〉 In the process of step ST9, the determination unit (25) determines whether the condition "ΔVC_s(2) < ΔVC" is satisfied. If this condition is met, the gradation difference ΔVC between the light part (51) and the dark part (52) in the second region (57) belongs to LEVEL(3) to LEVEL(7). When the gradation difference ΔVC belongs to LEVEL(3) to LEVEL(7), it corresponds to the degree of turbidity of the hydraulic oil being "low". Therefore, when this condition is satisfied, the determination unit (25) performs the process of step ST13. On the other hand, if this condition is not satisfied, the determination unit (25) performs the process of step ST10.

[0133] 〈Step ST10〉 In the process of step ST9, when the condition "ΔVC_s(2) < ΔVC" is not satisfied, the gradation difference ΔVC between the light 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 LEVEL(1) to LEVEL(2), it corresponds to the degree of turbidity of the hydraulic oil being "high". When the degree of turbidity of the hydraulic oil corresponds to "high", the determination unit (25) determines that "the degree of turbidity of the hydraulic oil is high and the hydraulic oil is in a state not suitable for use". Then, in the process of step ST10, the determination unit (25) starts the cause determination operation.

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

[0135] 〈Step ST11〉 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 operation. Then, the determination unit (25) determines whether the condition "VC_max(n) < VC_ave" is satisfied.

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

[0137] On the other hand, when the condition "VC_max(n) < VC_ave" is not satisfied, the gradation of the second region (57) of the determination image (50) approaches "black" as a whole. Therefore, the determination unit (25) determines that the cause of the turbidity of the hydraulic oil is "contamination of solid matter such as sludge" and performs the process of step ST15.

[0138] 〈Step ST12〉 The process of step ST12 is performed when it is determined in the process of step ST8 that the degree of turbidity of the hydraulic oil corresponds 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 displaying the information that "the hydraulic oil is substantially not turbid and the hydraulic oil is in a good state" on the display unit (21) of the main body unit (20). As this first display operation, the determination unit (25) performs an operation for "lighting the LED lamp, which is the display unit (21), in green". Note that the color of the light emitted by the display unit (21) is merely an example.

[0140] 〈Step ST13〉 The process of step ST13 is performed when it is determined in the process of step ST9 that the degree of turbidity of the hydraulic oil corresponds 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 display unit (21) of the main body unit (20) to display information that "the degree of turbidity of the hydraulic oil is low and the hydraulic oil is in a usable state". As this second display operation, the determination unit (25) performs, for example, an operation for lighting the LED lamp, which is the display unit (21), in orange. Note that the color of the light emitted by the display unit (21) is merely an example.

[0142] 〈Step ST14〉 The process of step ST14 is performed when it is determined in the process of step ST11 that the cause of the turbidity of the hydraulic oil 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 causing the display unit (21) of the main body unit (20) to display information indicating that the cause of the turbidity of the hydraulic oil is "mixing of water". As this third display operation, the determination unit (25) performs, for example, an operation for alternately lighting the LED lamp, which is the display unit (21), in red and blue. Note that the color of the light emitted by the display unit (21) is merely an example.

[0144] 〈Step ST15〉 The process of step ST15 is performed when it is determined in the process of step ST11 that the cause of the turbidity of the hydraulic oil is "mixing of solids".

[0145] In the process of step ST15, the determination unit (25) performs a fourth display operation. The fourth display operation is an operation for causing the display unit (21) of the main body unit (20) to display information indicating that the cause of the turbidity of the hydraulic oil is "mixing of solids such as sludge". As this fourth display operation, the determination unit (25) performs, for example, an operation for lighting the LED lamp, which is the display unit (21), in red. Note that the color of the light emitted by the display unit (21) is merely an example.

[0146] -Feature (1) of Embodiment 1- In the turbidity determination device (10) of the present embodiment, the camera (35) acquires an image of the member to be imaged (40) as a determination image (50). An operating oil to be the object of turbidity determination is interposed between the camera (35) and the member to be imaged (40). The gradation difference between the bright part (51) and the dark part (52) in the determination image (50) varies depending on the degree of turbidity of the operating oil between the imaging unit (35) and the member to be imaged (40). Therefore, the determination unit (25) determines the degree of turbidity of the operating oil based on the gradation difference between the bright part (51) and the dark part (52) in the determination image (50).

[0147] Note that the "gradation difference" in the description of the present embodiment is an index indicating the "difference in color shade". The meaning of the "gradation difference" in a grayscale image is substantially the same as the meaning of "contrast".

[0148] The turbidity determination device (10) of the present embodiment can determine the degree of turbidity of the operating oil as long as the operating oil to be the object of turbidity determination is between the imaging unit (35) and the member to be imaged (40). Therefore, by using this turbidity determination device (10), it is possible to determine the degree of turbidity of the operating oil without collecting a sample of the operating oil for inspection from the hydraulic equipment.

[0149] In particular, the turbidity determination device (10) of the present embodiment determines the degree of turbidity of the operating oil in a state where it is installed in the operating oil tank (60). Therefore, it is possible to continuously determine the state of the actually used operating oil and promptly notify the user or administrator of the hydraulic equipment when the state of the operating oil deteriorates. Therefore, according to the turbidity determination device (10) of the present embodiment, it is possible to provide information useful for preventing troubles in the hydraulic equipment caused by continuously using the deteriorated operating oil to the user or administrator of the hydraulic equipment.

[0150] - Feature (2) of Embodiment 1 - In the turbidity determination device (10) of the present embodiment, the determination unit (25) determines the color of the hydraulic oil by the color determination operation. Then, the determination unit (25) determines the degree of turbidity of the hydraulic oil by comparing the reference gradation difference ΔVC_r corresponding to the color of the hydraulic oil with the gradation difference ΔVC between the bright part (51) and the dark part (52) in the determination image (50) acquired by the imaging unit (35). Therefore, the turbidity determination device (10) of the present embodiment can appropriately determine the degree of turbidity of the hydraulic oil even when the color of the hydraulic oil changes during use.

[0151] In particular, the determination unit (25) of the present embodiment performs the color determination operation based on the first region (56) including only the bright part (51) of the determination image (50). Further, in the present embodiment, the ring part (41) of the member to be imaged (40) forming the bright part (51) of the determination image (50) is white. Therefore, the color of the first region (56) of the determination image (50) is substantially the same as the color of the hydraulic oil filling the determination space (32). Accordingly, in the turbidity determination device (10) of the present embodiment, the color of the hydraulic oil stored in the hydraulic oil tank (60) can be accurately determined by the color determination operation of the determination unit (25).

[0152] - Feature (3) of Embodiment 1 - In the turbidity determination operation, the determination unit (25) of the turbidity determination device (10) of the present embodiment determines the degree of turbidity of the hydraulic oil based on the gradation difference ΔVC between the bright part (51) and the dark part (52) in the second region (57) of the determination image (50).

[0153] In the second region (57) of the determination image (50) used in the turbidity determination operation, a plurality of bright portions (51) and dark portions (52) are included. The determination unit (25) of the present embodiment sets the difference between the maximum gradation value VC1, which is the maximum gradation value of the bright portions (51) in the second region (57), and the minimum gradation value VC2, which is the minimum gradation value of the dark portions (52) in the second region (57), as the gradation difference ΔVC (= VC1 - VC2) between the bright portions (51) and the dark portions (52) in the second region (57). Therefore, according to the present embodiment, the gradation difference ΔVC between the bright portions (51) and the dark portions (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 determined.

[0154] - Feature (4) of Embodiment 1 - In the turbidity determination device (10) of the present embodiment, the determination unit (25) performs a cause determination operation when the degree of turbidity of the hydraulic oil is high. In the cause determination operation, the determination unit (25) determines whether the cause of the turbidity of the hydraulic oil is "mixing of water" or "mixing of solids".

[0155] The countermeasures to be taken differ between the case where the cause of the turbidity of the hydraulic oil is "mixing of water" and the case where it is "mixing of solids". Therefore, the turbidity determination device (10) of the present embodiment can provide information for the user or administrator of the hydraulic equipment to determine the countermeasures to be taken by determining the cause of the turbidity of the hydraulic oil.

[0156] - Feature (5) of Embodiment 1 - Here, when the distance from the camera (35) to the member to be imaged (40) changes, the correlation between "the degree of turbidity of the hydraulic oil" and "the gradation difference ΔVC between the bright part (51) and the dark part (52) in the determination image (50)" changes. On the other hand, in the turbidity determination device (10) of the present embodiment, the member to be imaged (40) is fixed to the sheath tube (30) via the partition member (31), and the distance L from the camera (35) to the member to be imaged (40) is kept constant. Therefore, in the turbidity determination device (10) of the embodiment, the correlation between "the degree of turbidity of the hydraulic oil" and "the gradation difference ΔVC between the bright part (51) and the dark part (52) in the determination image (50)" can be kept constant, and the degree of turbidity of the hydraulic oil can be accurately determined.

[0157] -Feature (6) of Embodiment 1- In the turbidity determination device (10), the member to be imaged (40) is formed in a flat plate shape without a through hole (43), and white and black regions are formed on the upper surface of the member to be imaged (40), and the dark part (52) of the determination image (50) can be formed by this black region. However, in this case, if a white-like foreign object is placed on the black region of the member to be imaged (40), the determination unit (25) may erroneously determine the gradation value of the dark part (52) of the determination image (50) to be higher than the actual value, and as a result, there is a possibility of erroneously determining the degree of turbidity of the hydraulic oil.

[0158] In contrast, in the turbidity determination device (10) of the present embodiment, the through hole (43) of the member to be imaged (40) forms the dark part (52) of the determination image (50). No foreign object remains in the through hole (43) of the member to be imaged (40). Therefore, the determination unit (25) can accurately determine the gradation value of the dark part (52) of the determination image (50), and as a result, the degree of turbidity of the hydraulic oil can be accurately determined.

[0159] -Feature (7) of Embodiment 1- If a foreign object enters the determination space (32) between the camera (35) and the member to be photographed (40), there is a risk that the foreign object will be reflected in the determination image (50). If something other than the member to be photographed (40) is reflected in the determination image (50), the determination result of the color of the hydraulic oil in the color determination operation, the determination result of the degree of turbidity of the hydraulic oil in the turbidity determination operation, and the determination result of the cause of the turbidity of the hydraulic oil in the cause determination operation may become inaccurate.

[0160] On the other hand, in the turbidity determination device (10) of the present embodiment, the determination space (32) between the camera (35) and the member to be photographed (40) is surrounded by a wire mesh-like partition member (31). Therefore, while allowing the hydraulic oil to enter and exit the determination space (32), it is possible to prevent relatively large foreign objects from entering the determination space (32). Therefore, according to the turbidity determination device (10) of the present embodiment, the possibility of misjudgment due to foreign objects entering the determination space (32) can be reduced. As a result, it becomes possible to accurately perform the determination of the color of the hydraulic oil in the color determination operation, the determination of the degree of turbidity of the hydraulic oil in the turbidity determination operation, and the determination of the cause of the turbidity of the hydraulic oil in the cause determination operation.

[0161] -Modification Example of Embodiment 1- Regarding the turbidity determination device (10) of the above Embodiment 1, the following modification examples may be applied. Note that the following modification examples may be appropriately combined or replaced as long as the functions of the turbidity determination device (10) are not impaired.

[0162] 〈First Modification Example〉 The color of the member to be photographed (40) is not limited to white. However, it is desirable that the color of the portion forming the bright part (51) of the member to be photographed (40) be a color with high lightness.

[0163] 〈Second Modification Example〉 The shape of the bridge portion (42) of the member to be imaged (40) is not limited to a straight rod shape. For example, as shown in FIG. 13, the bridge portion (42) may be formed in an X shape. In the member to be imaged (40) shown in FIG. 13, four through holes (43) partitioned by the X-shaped bridge portion (42) are formed inside the ring portion (41).

[0164] <Third Modification Example> The member to be imaged (40) may be a flat plate member in which no through hole (43) is formed.

[0165] As shown in FIGS. 14 and 15, in the member to be imaged (40) of this modification example, a white region (44) and a black region (45) are formed on the surface facing the imaging unit (35). The white region (44) forms the bright part (51) of the determination image (50). The black region (45) forms the dark part (52) of the determination image (50).

[0166] In the member to be imaged (40) shown in FIG. 14, the surface facing the camera (35) is bisected into a white region (44) and a black region (45). In the member to be imaged (40) shown in FIG. 15, an annular white region (44) and a black region (45) are alternately arranged concentrically on the surface facing the camera (35).

[0167] <Fourth Modification Example> The turbidity determination device (10) of the present embodiment may be configured to display the determination results obtained in the turbidity determination operation and the cause determination operation of the determination unit (25) on an external device such as a smartphone. In this case, the turbidity determination device (10) is configured to be able to perform wireless communication with an external device such as a smartphone.

[0168] <<Embodiment 2>> The turbidity determination device (10) of Embodiment 2 will be described. Similar to the turbidity determination device (10) of Embodiment 1, the turbidity determination device (10) of the present embodiment is also a turbidity determination system (15).

[0169] As shown in FIG. 16, the turbidity determination device (10) of the present embodiment includes an imaging unit (70) and a determination unit (80). The imaging unit (70) and the determination unit (80) are electrically connected via a connection cable (85). The imaging unit (70) and the determination unit (80) communicate with each other via the connection cable (85). The imaging unit (70) is provided in the middle of a return pipe (63) connected to the hydraulic oil tank (60). The return pipe (63) is an oil pipe through which the hydraulic oil flows.

[0170] -Imaging Unit- The imaging unit (70) will be described with appropriate reference to FIGS. 17 to 21. In the following description, "up", "down", "right", "left", "front", and "rear" mean the directions shown in FIGS. 17 and 18.

[0171] As shown in FIGS. 17 and 18, the imaging unit (70) includes a case (71). Inside the case (71), a camera (35), a first light source (36a), a second light source (36b), a passage block (73), a member to be imaged (40), and a base plate (72) are accommodated. Further, a first joint member (75a) and a second joint member (75b) are connected to the passage block (73).

[0172] <Case> The case (71) is a rectangular parallelepiped box-shaped member. As shown in FIG. 18, the case (71) includes a case body (71a) and a case lid (71b). The case lid (71b) is disposed on the front side of the case body (71a) and covers the opening of the case body (71a). As shown in FIG. 17, a coupler (77) for connecting the connection cable (85) is provided on the side portion (the right side portion in the present embodiment) of the case (71).

[0173] The materials of the case body (71a) and the case lid (71b) constituting the case (71) are synthetic resins that do not transmit light. Note that the material of one or both of the case body (71a) and the case lid (71b) may be metal.

[0174] <Base Plate> The base plate (72) is a rectangular thick plate member. The material of the base plate (72) is a transparent synthetic resin (for example, acrylic resin).

[0175] As shown in FIGS. 17 and 18, the base plate (72) is housed in the case body (71a). The base plate (72) is fixed to the bottom of the case body (71a) in a posture substantially parallel to the bottom of the case body (71a). The base plate (72) is arranged at the central portion in the left - right direction of the case body (71a) with its long side in the vertical direction.

[0176] 〈Member to be photographed〉 As shown in FIG. 21, the member to be photographed (40) of the present embodiment is a rectangular sheet - like member. The material of the member to be photographed (40) is a white synthetic resin that does not transmit light.

[0177] On the surface of the member to be photographed (40), a determination graphic (46) is drawn. The determination graphic (46) of the present embodiment is a black grid - like graphic. This determination graphic (46) is composed of a plurality of slightly thick black vertical lines arranged at regular intervals and a plurality of slightly thick black horizontal lines arranged at regular intervals.

[0178] In the member to be photographed (40) of the present embodiment, the black determination graphic (46) forms the dark part (52) of the determination image (50), and the white part other than the determination graphic (46) forms the bright part (51) of the determination image (50).

[0179] As shown in FIGS. 18 and 20, the sheet - like member to be photographed (40) is attached to the front surface of the base plate (72) with the surface on which the determination graphic (46) is drawn facing forward. The member to be photographed (40) is arranged at the central portion in the vertical and horizontal directions of the base plate (72).

[0180] 〈Passage block〉 The passage block (73) is an intermediate member arranged between the member to be photographed (40) and the camera (35).

[0181] The passage block (73) is a rectangular parallelepiped-shaped block member. The passage block (73) is a hexahedron having six side faces. Each side face of the passage block (73) is substantially a flat surface. In the passage block (73), a pair of opposing side faces are substantially parallel. The material of the passage block (73) is a transparent synthetic resin (for example, acrylic resin).

[0182] As shown in FIGS. 18 and 19, an oil passage (74) for flowing hydraulic oil is formed in the passage block (73). The oil passage (74) is a through hole extending in the longitudinal direction of the passage block (73) (the vertical direction in FIG. 18). The cross section of the oil passage (74) is circular. One end of the oil passage (74) opens to one end face of the passage block (73) (the upper end face in FIG. 18). The other end of the oil passage (74) opens to the other end face of the passage block (73) (the lower end face in FIG. 18).

[0183] As shown in FIG. 18, the passage block (73) is disposed in front of the base plate (72). The passage block (73) is in close contact with the member to be photographed (40) attached to the base plate (72). As shown in FIG. 20, the passage block (73) covers the entire member to be photographed (40).

[0184] As shown in FIG. 18, in the passage block (73), the rear face in close contact with the member to be photographed (40) is the first side face (73a), and the front face on the side opposite to the member to be photographed (40) is the second side face (73b). In the passage block (73), the oil passage (74) is disposed between the first side face (73a) and the second side face (73b) that are parallel to each other.

[0185] <Camera> The camera (35) of the present embodiment is an imaging unit that acquires an image of the member to be photographed (40), similar to the camera (35) of the first embodiment. The camera (35) of the present embodiment includes a lens (35a) and acquires a color image.

[0186] As shown in FIGS. 17 and 18, the camera (35) is fixed to the case lid (71b) via the support plate (76). The camera (35) is also electrically connected to the coupler (77).

[0187] In the internal space of the case (71), the camera (35) is disposed in front of the passage block (73). The lens (35a) of the camera (35) faces the second side surface (73b) of the passage block (73). As also shown in FIG. 19, the lens (35a) of the camera (35) faces a region near the center in the vertical direction of the second side surface (73b).

[0188] The camera (35) faces the second side surface (73b) of the passage block (73) and acquires an image of the member to be photographed (40) disposed on the other side of the passage block (73) as a determination image (50). In other words, the camera (35) acquires an image of the member to be photographed (40) as seen from the second side surface (73b) side of the passage block (73) as the determination image (50).

[0189] 〈First light source, second light source〉 The first light source (36a) and the second light source (36b) are light sources (36) that emit light. Each of the first light source (36a) and the second light source (36b) is a white LED lamp.

[0190] The first light source (36a) and the second light source (36b) are fixed to the support plate (76) together with the camera (35). The first light source (36a) and the second light source (36b) are also electrically connected to the coupler (77).

[0191] In the internal space of the case (71), the first light source (36a), the camera (35), and the second light source (36b) are arranged in a line in order in the extending direction of the oil passage (74) (the vertical direction in FIGS. 17 and 18). In FIGS. 17 and 18, the first light source (36a) is disposed above the camera (35), and the second light source (36b) is disposed below the camera (35).

[0192] 〈First joint member, second joint member〉 As shown in FIGS. 18 and 19, each of the first joint member (75a) and the second joint member (75b) is a metal circular tubular member.

[0193] The first joint member (75a) penetrates the upper side portion of the case body (71a) in FIG. 18. One end portion (the lower end portion in FIG. 18) of the first joint member (75a) is inserted into the opening of the oil passage (74) on the upper surface of the passage block (73) in FIG. 18. The other end portion (the upper end portion in FIG. 18) of the first joint member (75a) is connected to the return pipe (63) through which the hydraulic oil flows.

[0194] The second joint member (75b) penetrates the lower side portion of the case body (71a) in FIG. 18. One end portion (the upper end portion in FIG. 18) of the second joint member (75b) is inserted into the opening of the oil passage (74) on the lower surface of the passage block (73) in FIG. 18. The other end portion (the lower end portion in FIG. 18) of the second joint member (75b) is connected to the return pipe (63) through which the hydraulic oil flows.

[0195] -Determination Unit- As shown in FIG. 16, the determination unit (80) includes a determination section (25) and a display section (21).

[0196] 〈Determination Section〉 The determination section (25) of the present embodiment is configured in the same manner as the determination section (25) of the first embodiment. Specifically, the determination section (25) of the present embodiment includes a CPU (26) and a memory device (27).

[0197] The determination section (25) of the present embodiment performs the same operations as the determination section (25) of the first embodiment. Specifically, the determination section (25) of the present embodiment performs a color determination operation, a turbidity determination operation, and a cause determination operation using the determination image (50).

[0198] 〈Display Section〉 The display section (21) of the present embodiment is one or more LED lamps, similar to the display section (21) of the first embodiment.

[0199] -Operation of the turbidity determination device- The operation of the turbidity determination device (10) will be described.

[0200] The turbidity determination device (10) performs the operations described below with the imaging unit (70) in a state where the hydraulic oil is passing through. The hydraulic oil flowing through the return pipe (63) flows into the oil passage (74) of the passage block (73) through the first joint member (75a), and flows through the oil passage (74). The hydraulic oil that has passed through the oil passage (74) flows out from the imaging unit (70) through the second joint member (75b), and flows into the hydraulic oil tank (60) again through the return pipe (63).

[0201] In the turbidity determination device (10), the camera (35) which is an imaging unit acquires an image of the member to be imaged (40) as a determination image (50). Further, in the turbidity determination device (10), the determination unit (25) performs a color determination operation, a turbidity determination operation, and a cause determination operation based on the determination image (50). The determination unit (25) performs the color determination operation and the turbidity determination operation in order. Further, when the determination unit (25) determines that the degree of turbidity of the hydraulic oil is high (in other words, the state of the hydraulic oil is bad) in the turbidity determination operation, the cause determination operation is performed. These operations are the same as the operations performed by the turbidity determination device (10) of Embodiment 1.

[0202] 〈Determination image〉 As described above, the camera (35) acquires an image of the member to be imaged (40) as a determination image (50). The camera (35) transmits the acquired determination image (50) to the determination unit (25). The determination unit (25) stores the determination image (50) received from the camera (35) in the memory device (27) as a color image with 256 gradations for each of R (red), G (green), and B (blue). Note that the gradations of RGB shown here are merely an example.

[0203] The light emitted by the first light source (36a) and the second light source (36b) passes through the transparent passage block (73), hits the member to be imaged (40), and is reflected. The light reflected by hitting the member to be imaged (40) passes through the passage block (73) and the hydraulic oil flowing through the oil passage (74), and enters the camera (35).

[0204] An example of the determination image (50) acquired by the camera (35) is shown in FIGS. 22 and 23. The determination image (50) is an image of the plane of the member to be photographed (40). In the member to be photographed (40), the portion corresponding to the black determination figure (46) drawn on the surface of the member to be photographed (40) becomes a dark portion (52) with a relatively low brightness. Also, in the member to be photographed (40), the portion corresponding to the white region other than the determination figure (46) on the surface of the member to be photographed (40) becomes a bright portion (51) with a relatively high brightness.

[0205] 〈Color determination operation〉 The color determination operation will be described. The color determination operation is “an operation in which the determination unit (25) determines the color of the hydraulic oil based on the determination image (50)”.

[0206] As shown in FIG. 22, the determination unit (25) sets four first regions (56) in the determination image (50) which is a color image. The first region (56) is a part of the determination image (50) and includes only the bright portion (51). Note that the number of the first regions (56) is merely an example and may be one. The determination unit (25) sets the first region (56) in the portion corresponding to the region other than the determination figure (46) of the member to be photographed (40) in the determination image (50).

[0207] The determination unit (25) determines the color of the hydraulic oil based on the ASTM color. The process for determining the color of the hydraulic oil is the same as the process performed by the determination unit (25) in Embodiment 1. Specifically, the determination unit (25) calculates the average value of the gradation values of each of RGB for all the first regions (56). Then, the determination unit (25) determines which of “transparent”, “yellow”, “goldenrod”, and “black” the color of the hydraulic oil corresponds to based on the average value of the gradation values of each of RGB regarding the calculated first region (56).

[0208] 〈Turbidity determination operation〉 The turbidity determination operation will be described. The turbidity determination operation is “an operation in which the determination unit (25) determines the degree of turbidity of the hydraulic oil based on the determination image (50)”.

[0209] The turbidity determination operation performed by the determination unit (25) of the present embodiment is the same as the turbidity determination operation performed by the determination unit (25) of the first embodiment. However, the second region (57) set by the determination unit (25) of the present embodiment in the turbidity determination operation is different from the second region (57) set by the determination unit (25) of the first embodiment in the turbidity determination operation.

[0210] The second region (57) set by the determination unit (25) of the present embodiment in the turbidity determination operation will be described with reference to FIG. 23.

[0211] The second region (57) is a part of the determination image (50). The second region (57) is a linear region located at the center in the left - right direction of the determination figure (46) reflected in the determination image (50). The second region (57) is located in the portion of the determination figure (46) reflected in the determination image (50) that overlaps with the oil passage (74) when viewed from the second side surface (73b) side of the passage block (73).

[0212] The second region (57) crosses a plurality of horizontal lines constituting the determination figure (46). Therefore, in the second region (57), the dark part (52) formed by the determination figure (46) and the bright part (51) formed by the part of the member to be imaged (40) other than the determination figure (46) appear alternately from one end to the other end of the second region (57).

[0213] In the turbidity determination operation, the determination unit (25) of the present embodiment, similar to 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 level shown in FIG. 11 the calculated gradation difference ΔVC belongs to. Then, the determination unit (25) determines which of "substantially none", "low", and "high" the degree of turbidity of the hydraulic oil corresponds to according to the level to which the gradation difference ΔVC belongs.

[0214] 〈Cause determination operation〉 When the determination unit (25) determines that "the degree of turbidity of the hydraulic oil is high and the hydraulic oil is not suitable for use", it performs a cause determination operation. The cause determination operation is "an 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 identification operation, the determination unit (25) of the present embodiment calculates the average value VC_ave of the gradation values in the second region (57) of the determination image (50) in the same manner as the determination unit (25) of the first embodiment, and compares the calculated average value VC_ave of the gradation values of the second region (57) with the 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 "contamination with water". Further, when the average value VC_ave of the gradation values in the second region (57) is less than or equal to 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 "contamination with solids such as sludge".

[0217] -Overall flow of the operation of the turbidity determination device- The overall flow of the operation of the turbidity determination device (10) of the present embodiment is the same as the overall flow 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 displays the results obtained by the turbidity determination operation and the cause determination operation on a display unit (21) constituted by an LED lamp.

[0218] -Feature (1) of the second embodiment- Similar to the turbidity determination device (10) of the first embodiment, the turbidity determination device (10) of the present embodiment can determine the degree of turbidity of the hydraulic oil if the hydraulic oil to be subjected to turbidity determination is between the imaging unit (35) and the member to be imaged (40). Therefore, by using this turbidity determination device (10), it is possible to determine the degree of turbidity of the hydraulic oil without collecting a sample of the hydraulic oil for inspection from the hydraulic equipment.

[0219] In particular, the turbidity determination device (10) of the present embodiment determines the degree of turbidity of the hydraulic oil that returns to the hydraulic oil tank (60) through the return pipe (63). Therefore, it is possible to continuously determine the state of the actually used hydraulic oil, and when the state of the hydraulic oil deteriorates, it is possible to promptly notify the user or administrator of the hydraulic equipment. Therefore, according to the turbidity determination device (10) of the present embodiment, it is possible to provide information useful for preventing troubles in hydraulic equipment caused by continuing to use deteriorated hydraulic oil to the user or administrator of the hydraulic equipment.

[0220] Further, according to the turbidity determination device (10) of the present embodiment, the same effects as those of the turbidity determination device (10) of the first embodiment can be obtained.

[0221] - Feature (2) of Embodiment 2 - In the turbidity determination device (10) of the present embodiment, the hydraulic oil to be subjected to turbidity determination flows through the oil passage (74) formed in the passage block (73), and the camera (35) and the member to be photographed (40) are arranged outside the passage block (73). Therefore, in the turbidity determination device (10) of the present embodiment, the hydraulic oil to be subjected to turbidity determination does not come into contact with the member to be photographed (40) and the camera (35).

[0222] Here, if foreign matter contained in the hydraulic oil adheres to the member to be photographed (40) or the camera (35), it becomes impossible to obtain a determination image (50) that accurately reflects the state of the hydraulic oil, and there is a risk of misjudging the state of the hydraulic oil.

[0223] On the other hand, in the turbidity determination device (10) of the present embodiment, since the hydraulic oil to be subjected to turbidity determination does not come into contact with the member to be photographed (40) and the camera (35), foreign matter contained in the hydraulic oil does not adhere to the member to be photographed (40) and the imaging unit (35). Therefore, according to the present embodiment, the accuracy of determining the state of the hydraulic oil can be improved.

[0224] - Feature (3) of Embodiment 2 - In the turbidity determination device (10) of the present embodiment, the first side surface (73a) of the passage block (73) in contact with the member to be photographed (40) is a flat surface. The camera (35) faces the second side surface (73b) of the passage block (73) and acquires an image of the member to be photographed (40) arranged on the other side of the passage block (73) as a determination image (50). The second side surface (73b) of the passage block (73) is a flat surface parallel to the first side surface (73a). Therefore, an image of the member to be photographed (40) with relatively little distortion can be acquired by the camera (35) as the determination image (50).

[0225] Therefore, according to the present embodiment, the turbidity determination device (10) can determine the state of the hydraulic oil using the determination image (50) with little distortion, and the accuracy of determining the state of the hydraulic oil can be improved.

[0226] - Feature (4) of Embodiment 2 - In the turbidity determination device (10) of the present embodiment, the member to be photographed (40), the camera (35), the passage block (73), the first light source (36a), and the second light source (36b) are arranged in the case (71). The case (71) does not transmit light. Inside the case (71), the camera (35) acquires an image of the member to be photographed (40) that has received only the light emitted by 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 member to be photographed (40) without being affected by the light outside the case (71).

[0227] Therefore, according to the turbidity determination device (10) of the present embodiment, the state of the hydraulic oil can be determined using the determination image (50) that accurately reflects the state of the hydraulic oil, and the accuracy of determining the state of the hydraulic oil can be improved.

[0228] - Feature (5) of Embodiment 2 - In the turbidity determination device (10) of this embodiment, in the internal space of the case (71), the first light source (36a), the camera (35), and the second light source (36b) are arranged in a line along the linear oil passage (74). The camera (35) acquires an image of the photographed member (40) that has received the light emitted by each of 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 member (40) that has received light with relatively uniform intensity as the determination image (50).

[0229] If the intensity of the light hitting the photographed member (40) is uniform, the camera (35) can be made to acquire a determination image (50) that accurately reflects the state of the hydraulic oil. Therefore, according to the turbidity determination device (10) of this embodiment, the state of the hydraulic oil can be determined using the determination image (50) that accurately reflects the state of the hydraulic oil, and the accuracy of the determination of the state of the hydraulic oil can be improved.

[0230] -Modification Example of Embodiment 2- Regarding the turbidity determination device (10) of the above-described Embodiment 2, the following modification examples may be applied. Note that the following modification examples may be appropriately combined or replaced as long as the functions of the turbidity determination device (10) are not impaired.

[0231] 〈First Modification Example〉 As shown in FIG. 18, in the imaging unit (70) of the turbidity determination device (10) of this embodiment, the lens (35a) of the camera (35) is separated from the second side surface (73b) of the passage block (73). However, the arrangement of the camera (35) and the passage block (73) in the imaging unit (70) is not limited to the arrangement shown in FIG. 18.

[0232] For example, in the imaging unit (70), the camera (35) may be arranged such that its lens (35a) contacts the second side surface (73b) of the passage block (73). Also, as shown in FIG. 24, a cylindrical lens hood (38) may be provided at the tip of the lens (35a) of the camera (35). In this case, it is desirable to arrange the camera (35) at a position where the tip of the lens hood (38) (the end opposite to the lens (35a)) contacts the second side surface (73b) of the passage block (73).

[0233] In a state where the lens (35a) or the lens hood (38) contacts the second side surface (73b) of the passage block (73), the light reflected by the second side surface (73b) of the passage block (73) does not enter the camera (35). Therefore, the camera (35) can acquire an image of the member to be imaged (40) without being affected by the light reflected by the second side surface (73b) of the passage block (73). Accordingly, according to the turbidity determination device (10) of this modified example, the state of the hydraulic oil can be determined using the determination image (50) that accurately reflects the state of the hydraulic oil, and the accuracy of the determination of the state of the hydraulic oil can be improved.

[0234] <Second Modified Example> In the turbidity determination device (10) of the present embodiment, the determination graphic (46) drawn on the member to be imaged (40) is not limited to the grid-like graphic shown in FIG. 21.

[0235] For example, the determination graphic (46) may be the graphic shown in FIG. 25 or FIG. 26. The determination graphics (46) shown in FIGS. 25 and 26 are composed of a single rectangular frame and a plurality of horizontal lines parallel to each other. In these determination graphics (46), the plurality of horizontal lines are arranged at regular intervals. In the determination graphic (46) shown in FIG. 25, the plurality of horizontal lines are substantially parallel to the short side of the frame. In the determination graphic (46) shown in FIG. 26, the plurality of horizontal lines are inclined with respect to the short side of the frame.

[0236] <Third Modified Example> As shown in FIG. 27, in the turbidity determination device (10) of the present embodiment, the determination unit (25) and the display unit (21) may be provided in the imaging unit (70). In the turbidity determination device (10) of this modification, the determination unit (25) is disposed in the internal space of the case (71), the display unit (21) is disposed on the outer surface of the case (71), and the determination unit (80) is omitted.

[0237] <Fourth Modification> The turbidity determination device (10) of the present embodiment may be configured to display the determination results obtained in the turbidity determination operation and the cause determination operation of the determination unit (25) on an external device such as a smartphone. In this case, the turbidity determination device (10) is configured to be able to perform wireless communication with an external device such as a smartphone.

[0238] <Fifth Modification> In FIG. 16, the imaging unit (70) of the turbidity determination device (10) is installed in the return pipe (63) in a posture where the first joint member (75a) is located above and the second joint member (75b) is located below. However, the posture of the imaging unit (70) in the state of being installed in the return pipe (63) is not limited to the posture shown in FIG. 16. The posture of the imaging unit (70) may be, for example, a posture in which the extension directions of the first joint member (75a) and the second joint member (75b) are substantially horizontal, or a posture in which the extension directions of the first joint member (75a) and the second joint member (75b) are inclined with respect to the vertical direction.

[0239] <<Other Embodiments>> For the turbidity determination device (10) of the above-described Embodiments 1 and 2, the following modifications may be applied. Note that the following modifications may be appropriately combined or replaced as long as the functions of the turbidity determination device (10) are not impaired.

[0240] - First Modification - In the turbidity determination device (10) of the above-described Embodiments 1 and 2, the determination unit (25) may be configured by a general-purpose computer that executes an application program. In this specification, "computer" refers to "a machine that stores a program describing a calculation procedure (algorithm) and executes calculations according to the stored program." Therefore, the "computer" in this specification includes large computers, personal computers, tablet computers, smartphones, and the like.

[0241] FIG. 28 shows the turbidity determination device (10) of Embodiment 2 to which this modified example is applied. This turbidity determination device (10) is also a turbidity determination system (15). In the turbidity determination device (10) shown in FIG. 28, the determination unit (80) is omitted, and the smartphone (92) constitutes the determination unit (25).

[0242] In the turbidity determination device (10) shown in FIG. 28, the imaging unit (70) includes a communication module (91). The communication module (91) performs wireless communication based on a communication standard such as Wi-Fi (registered trademark). The imaging unit (70) of this modified example transmits the determination image (50) acquired by the camera (35) to the smartphone (92) that constitutes the determination unit (25) via a communication line (93) such as the Internet.

[0243] An application program for causing the smartphone (92) to function as the determination unit (25) and the display unit (21) is installed in the smartphone (92). The smartphone (92) that functions as the determination unit (25) determines the state of the hydraulic oil based on the determination image (50) and displays the determined result on the display of the smartphone (92). In this modified example, the display of the smartphone (92) constitutes the display unit (21).

[0244] -Second Modified Example- In the turbidity determination device (10) of the above-described Embodiments 1 and 2, the determination unit (25) may be configured to determine the state of the hydraulic oil by so-called machine learning.

[0245] In the turbidity determination device (10) of this modification example, a learned model is recorded in the memory device (27) of the determination unit (25). This learned model is generated by machine learning that uses a number of determination images (50) of hydraulic oil in various states as input data and the state of the hydraulic oil corresponding to each determination image (50) as teacher data.

[0246] The determination unit (25) of this modification example inputs the determination image (50) acquired by the camera (35) into the learned model to determine which of "substantially none", "low", and "high" the degree of turbidity of the hydraulic oil corresponds to. When the degree of turbidity of the hydraulic oil corresponds to "high", it is also determined whether the cause of the turbidity of the hydraulic oil is "water contamination" or "solid contamination".

[0247] Although the embodiments and modification examples have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Also, the elements according to the above embodiments, modification examples, and other embodiments may be combined or replaced as appropriate. In addition, the descriptions "first" and "second" in the specification and claims are used to distinguish the clauses to which these descriptions are attached, and do not limit even the number and order of those clauses.

Industrial Applicability

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

Explanation of Reference Numerals

[0249] 10 Turbidity determination device 15 Turbidity determination system 25 Determination unit 31 Partition member 35 Camera (imaging unit) 36 Light source 36a First light source 36b Second light source 40 Member to be imaged 43 Through-hole 50 Judgment image 51 Light part 52 Dark part 56 First area 57 Second area 71 Case 73 Intermediate member 73a First side surface 73b Second side surface 74 Oil passage 75a First joint member 75b Second joint member

Claims

1. A turbidity determination device (10) for determining the turbidity of the hydraulic fluid of a hydraulic machine, comprising: A member to be imaged (40) that forms a light part (51) and a dark part (52); An imaging unit (35) provided at a position away from the member to be imaged (40) such that the hydraulic fluid is present between the imaging unit and the member to be imaged (40), and acquiring an image of the member to be imaged (40) as a determination image (50); A determination unit (25) that performs a turbidity determination operation for determining the degree of turbidity of the hydraulic fluid based on the gradation difference between the light part (51) and the dark part (52) in the determination image (50) acquired by the imaging unit (35). The turbidity determination operation is an operation in which the determination unit (25) determines the degree of turbidity of the hydraulic fluid by comparing the gradation difference between the light part (51) and the dark part (52) in the determination image (50) with a reference gradation difference. The reference gradation difference is the gradation difference between the light part (51) and the dark part (52) in the determination image (50) acquired by the imaging unit (35) when the hydraulic fluid in a non-turbid state is present between the member to be imaged (40) and the imaging unit (35). Turbidity determination device.

2. A turbidity determination device (10) for determining the turbidity of the hydraulic fluid of a hydraulic machine, comprising: A member to be imaged (40) that forms a light part (51) and a dark part (52); An imaging unit (35) provided at a position away from the member to be imaged (40) such that the hydraulic fluid is present between the imaging unit and the member to be imaged (40), and acquiring an image of the member to be imaged (40) as a determination image (50); A determination unit (25) that performs a turbidity determination operation for determining the degree of turbidity of the hydraulic fluid based on the gradation difference between the light part (51) and the dark part (52) in the determination image (50) acquired by the imaging unit (35). The turbidity determination operation is an operation in which the determination unit (25) determines the degree of turbidity of the hydraulic fluid by comparing the gradation difference between the light part (51) and the dark part (52) in the determination image (50) with a reference gradation difference. The determination unit (25) is configured to: Perform a color determination operation for determining the color of the hydraulic fluid based on the determination image (50); In the turbidity determination operation, compare the gradation difference between the light part (51) and the dark part (52) in the determination image (50) with the reference gradation difference corresponding to the color of the hydraulic fluid determined in the color determination operation. Turbidity determination device.

3. A portion of the determination image (50) that only includes the bright portion (51) is the first region (56). The color determination operation is an operation in which the determination unit (25) determines the color of the hydraulic oil based on the first region (56) of the determination image (50). The turbidity determination device according to claim 2.

4. A turbidity determination device (10) for determining the turbidity of the hydraulic oil of hydraulic equipment, A photographed member (40) that forms a bright portion (51) and a dark portion (52), An imaging unit (35) provided at a position away from the photographed member (40) so that the hydraulic oil exists between the imaging unit (35) and the photographed member (40), and acquiring an image of the photographed member (40) as a determination image (50). A determination unit (25) that performs a turbidity determination operation for determining the degree of turbidity of the hydraulic oil based on the gradation difference between the bright portion (51) and the dark portion (52) in the determination image (50) acquired by the imaging unit (35). The photographed member (40) forms a plurality of bright portions (51) and a plurality of dark portions (52). A region of the determination image (50) that includes a plurality of bright portions (51) and a plurality of dark portions (52) is the second region (57). In the turbidity determination operation, the determination unit (25) determines the degree of turbidity of the hydraulic oil based on the difference between the maximum value of the gradation value of the bright portion (51) and the minimum value of the gradation value of the dark portion (52) in the second region (57). Turbidity determination device.

5. A turbidity determination device (10) for determining the turbidity of the hydraulic oil of hydraulic equipment, A photographed member (40) that forms a bright portion (51) and a dark portion (52), An imaging unit (35) provided at a position away from the photographed member (40) so that the hydraulic oil exists between the imaging unit (35) and the photographed member (40), and acquiring an image of the photographed member (40) as a determination image (50). A determination unit (25) that performs a turbidity determination operation for determining the degree of turbidity of the hydraulic oil based on the gradation difference between the bright portion (51) and the dark portion (52) in the determination image (50) acquired by the imaging unit (35). The determination unit (25) performs a cause determination operation for determining the cause of the turbidity of the hydraulic oil. Turbidity determination device.

6. A region of the determination image (50) that includes both the bright portion (51) and the dark portion (52) is the second region (57). The cause determination operation is an operation in which the determination unit (25) determines the cause of the turbidity of the hydraulic oil based on the average value of the gradation values in the second region (57) of the determination image (50). The turbidity determination device according to claim 5.

7. The member to be imaged (40) forms a plurality of bright portions (51) and a plurality of dark portions (52). The second region (57) is a region of the determination image (50) that includes a plurality of the bright portions (51) and the dark portions (52). The turbidity determination device according to claim 6.

8. The cause determination operation is an operation in which the determination unit (25) determines the cause of the turbidity of the hydraulic oil by comparing the average of the gradation values in the second region (57) of the determination image (50) with a reference gradation value. The turbidity determination device according to claim 6.

9. The reference gradation value is the gradation value of the bright portion (51) in the determination image (50) acquired by the imaging unit (35) in a state where the hydraulic oil in a non-turbid state exists between the member to be imaged (40) and the imaging unit (35). The turbidity determination device according to claim 8.

10. In the cause determination operation, when the average value of the gradation values in the second region (57) of the determination image (50) is higher than the reference gradation value, the determination unit (25) determines that the cause of the turbidity of the hydraulic oil is the mixing of water into the hydraulic oil. The turbidity determination device according to claim 8.

11. In the cause determination operation, when the average value of the gradation values in the second region of the determination image (50) is lower than the reference gradation value, the determination unit (25) determines that the cause of the turbidity of the hydraulic oil is the mixing of solids into the hydraulic oil. The turbidity determination device according to claim 8.

12. A turbidity determination device (10) for determining the turbidity of the hydraulic oil of a hydraulic device, a member to be imaged (40) that forms a bright portion (51) and a dark portion (52), an imaging unit (35) provided at a position away from the member to be imaged (40) so that the hydraulic oil exists between the imaging unit (35) and the member to be imaged (40), and acquiring an image of the member to be imaged (40) as a determination image (50), and a determination unit (25) that performs a turbidity determination operation for determining the degree of turbidity of the hydraulic oil based on the gradation difference between the bright portion (51) and the dark portion (52) in the determination image (50) acquired by the imaging unit (35). The photographed member (40) is formed with a through hole (43) that opens to a surface facing the imaging unit (35), a portion of the photographed member (40) other than the through hole (43) forms the light portion (51), and the through hole (43) forms the dark portion (52). Turbidity determination device.

13. A plurality of through holes (43) are formed in the photographed member (40). The turbidity determination device according to claim 12.

14. The photographed member (40) is white. The turbidity determination device according to claim 12.

15. A turbidity determination device (10) for determining the turbidity of hydraulic oil of hydraulic equipment, a photographed member (40) that forms a light portion (51) and a dark portion (52), an imaging unit (35) provided at a position away from the photographed member (40) so that the hydraulic oil exists between the imaging unit (35) and the photographed member (40), and acquiring an image of the photographed member (40) as a determination image (50), a determination unit (25) that performs a turbidity determination operation for determining the degree of turbidity of the hydraulic oil based on the gradation difference between the light portion (51) and the dark portion (52) in the determination image (50) acquired by the imaging unit (35), the photographed member (40) is fixed to the imaging unit (35), a net-like partition member (31) that surrounds a space (32) between the photographed member (40) and the imaging unit (35) is provided. Determination device.

16. A turbidity determination device (10) for determining the turbidity of hydraulic oil of hydraulic equipment, a photographed member (40) that forms a light portion (51) and a dark portion (52), an imaging unit (35) provided at a position away from the photographed member (40) so that the hydraulic oil exists between the imaging unit (35) and the photographed member (40), and acquiring an image of the photographed member (40) as a determination image (50), a determination unit (25) that performs a turbidity determination operation for determining the degree of turbidity of the hydraulic oil based on the gradation difference between the light portion (51) and the dark portion (52) in the determination image (50) acquired by the imaging unit (35), an intermediate member (73) disposed between the photographed member (40) and the imaging unit (35), made of a transparent material, and having an oil passage (74) formed therein for flowing the hydraulic oil. Turbidity determination device.

17. The intermediate member (73) has a first side surface (73a) and a second side surface (73b), each of the first side surface (73a) and the second side surface (73b) is a flat surface. The first side surface (73a) and the second side surface (73b) are parallel to each other. In the intermediate member (73), the oil passage (74) is arranged between the first side surface (73a) and the second side surface (73b). The member to be photographed (40) is provided in contact with the first side surface (73a) of the intermediate member (73). The imaging unit (35) is provided at a position facing the second side surface (73b) of the intermediate member (73). The turbidity determination device according to claim 16.

18. A first joint member (75a) that communicates with one end of the oil passage (74) and is connected to an oil pipe (63) through which the hydraulic oil flows, and a second joint member (75b) that communicates with the other end of the oil passage (74) and is connected to the oil pipe (63). The turbidity determination device according to claim 16.

19. A case (71) that houses the member to be photographed (40), the imaging unit (35), and the intermediate member (73) is provided. The turbidity determination device according to claim 16.

20. A light source (36) that is housed in the case (71) and emits light is provided. The case (71) is made of a material that does not transmit light. The turbidity determination device according to claim 19.

21. The oil passage (74) in the intermediate member (73) is a linear passage. The light source (36) includes a first light source (36a) and a second light source (36b). The first light source (36a), the imaging unit (35), and the second light source (36b) are arranged in a row in order along the extension direction of the oil passage (74). The turbidity determination device according to claim 20.

Images