Fluid property detection device and method of manufacturing fluid property detection device

Abstract

To provide a fluid property detection device which can be reduced in size while minimizing detection accuracy deterioration.SOLUTION: A fluid property detection device 1 is provided, comprising tabular first electrode plates 20, tabular second electrode plates 30, and a substrate unit 3 configured to generate a signal corresponding to properties of a detection target fluid on the basis of electrical characteristics between the first electrode plates 20 and the second electrode plates 30, where the first electrode plates 20 and the second electrode plates 30 are alternately stacked with a given space therebetween.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fluid property detection device and a method for manufacturing a fluid property detection device. [Background technology]

[0002] Patent Document 1 discloses a fuel sensor that detects the properties of fuel. The fuel sensor of Patent Document 1 detects the properties of fuel by detecting the electrostatic capacitance (electrical characteristic) of the fuel between a cylindrical outer electrode and a cylindrical inner electrode provided radially inside the outer electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-195160 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the fuel sensor described in Patent Document 1, in order to reduce the size of the fuel sensor, it is necessary to reduce the size of the outer electrode and the inner electrode. However, when the outer electrode and the inner electrode are reduced in size, the capacitance is reduced, which may deteriorate the detection accuracy of the fuel sensor.

[0005] The present invention has been made in consideration of the above problems, and has an object to reduce the size of a fluid property detection device while suppressing a decrease in detection accuracy. [Means for solving the problem]

[0006] The present invention is a fluid property detection device that detects the properties of a fluid to be detected, and is characterized in that it comprises a plate-shaped first electrode plate, a plate-shaped second electrode plate, and a signal generating unit that generates a signal corresponding to the properties of the fluid to be detected based on the electrical characteristics between the first electrode plate and the second electrode plate, and the first electrode plate and the second electrode plate are stacked alternately at a predetermined interval.

[0007] In this invention, the first electrode plate and the second electrode plate are alternately stacked at a predetermined interval, so that the total surface area of ​​each of the first electrode plate and the multiple second electrode plates can be sufficiently secured, which makes it possible to miniaturize the fluid property detection device while suppressing deterioration of the electrical characteristics (detection accuracy).

[0008] The present invention is characterized by further comprising a spacer provided between adjacent first and second electrode plates to maintain a distance between the adjacent first and second electrode plates.

[0009] In this invention, the spacer can reliably maintain the distance between the adjacent first and second electrode plates.

[0010] In addition, the present invention is characterized in that the first electrode plate and the second electrode plate have the same shape.

[0011] In this invention, for example, when the first electrode plate and the second electrode plate are formed using a mold, these molds are common, so that the mold cost can be suppressed. Also, by using a common mold, the manufacturing method is also common, so that the manufacturing cost can be reduced. Furthermore, since the number of types of parts is reduced, inventory management is also simplified. Also, since the dimensional variation of the first electrode plate and the second electrode plate is stabilized, their electrostatic capacitance is stabilized.

[0012] The present invention is also characterized in that the first electrode plate and the second electrode plate each have an insertion hole, and further include a guide portion that passes through the insertion hole of the first electrode plate and the insertion hole of the second electrode plate and restricts movement of the first electrode plate and the second electrode plate in a direction perpendicular to the stacking direction of the first electrode plate and the second electrode plate.

[0013] In this invention, when stacking the first electrode plate and the second electrode plate, the guide portion can restrict movement of the first electrode plate and the second electrode plate in a direction perpendicular to the stacking direction, thereby improving assembly efficiency and shortening assembly time.

[0014] The present invention also includes a first terminal electrically connecting the first electrode plate and the signal generating unit, and a second terminal electrically connecting the second electrode plate and the signal generating unit, wherein the first electrode plate has a first insertion hole through which the first terminal is inserted and a first avoidance portion formed to avoid contact with the second terminal when the first electrode plate and the second electrode plate are stacked, and the second electrode plate has a second insertion hole through which the second terminal is inserted and a second avoidance portion formed to avoid contact with the first terminal when the first electrode plate and the second electrode plate are stacked.

[0015] In this invention, it is possible to prevent the second terminal from interfering with the first electrode plate, and it is also possible to prevent the first terminal from interfering with the second electrode plate.

[0016] The present invention also relates to a manufacturing method for a fluid property detection device for detecting the properties of a fluid to be detected, the method comprising the steps of: a stacking process for alternately stacking a plate-shaped first electrode plate and a second electrode plate having the same shape as the first electrode plate, while maintaining a predetermined gap between them and inverting them 180° circumferentially; a first connection process for electrically connecting the first electrode plate to a first terminal; a second connection process for electrically connecting the second electrode plate to a second terminal; and a third connection process for electrically connecting a signal generating unit that generates a signal corresponding to the properties of the fluid to be detected based on the electrical characteristics between the first electrode plate and the second electrode plate, and the first terminal and the second terminal.

[0017] In this invention, the first electrode plate and the second electrode plate are alternately stacked at a predetermined interval, so that the total surface area of ​​each of the first electrode plate and the multiple second electrode plates can be sufficiently secured, which makes it possible to miniaturize the fluid property detection device while suppressing deterioration of the electrical characteristics (detection accuracy). Effect of the Invention

[0018] According to the present invention, it is possible to reduce the size of a fluid property detection device while suppressing a decrease in detection accuracy. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a cross-sectional view of a fluid property detection device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a detection portion of the fluid property detection device according to the embodiment of the present invention. [Diagram 3] FIG. 3 is a plan view of an electrode plate according to an embodiment of the present invention. [Figure 4] FIG. 4 is a plan view of an electrode plate according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, a fluid property detection device 1 according to an embodiment of the present invention will be described with reference to the drawings.

[0021] The fluid property detection device 1 detects the properties of hydraulic oil as a working fluid that drives a hydraulic actuator such as a hydraulic cylinder. The hydraulic actuator is driven by hydraulic oil supplied from a hydraulic pump driven by an engine, an electric motor, or the like. The fluid property detection device 1 is attached to a pipe through which the hydraulic oil flows, a tank that stores the hydraulic oil, or the like. Note that, in the following, a case will be described in which the fluid property detection device 1 detects the properties of hydraulic oil in a pipe P as the fluid to be detected, but the fluid to be detected by the fluid property detection device 1 is not limited to hydraulic oil, and may be various liquids such as lubricating oil, cutting oil, fuel, solvent, and chemicals, or gas.

[0022] First, a specific configuration of a fluid property detection device 1 will be described with reference to Figures 1 and 2. Figure 1 is a cross-sectional view of the fluid property detection device 1. Figure 2 is an enlarged cross-sectional view of a detection section S in the fluid property detection device 1.

[0023] As shown in Figures 1 and 2, the fluid property detection device 1 has a housing 10 attached to a piping P, a detection unit 2, a board unit 3 as a signal generating unit electrically connected to the detection unit 2, a cylindrical cover 4 covering the board unit 3, an end cover 5 that closes the opening of the cylindrical cover 4, and a mounting plate 40 fixed to the housing 10 by screws or the like.

[0024] The detection unit 2 has a detection section S having a plurality of plate-shaped first electrode plates 20 and a plurality of plate-shaped second electrode plates 30, a first terminal 50 that electrically connects the plurality of first electrode plates 20 to the board unit 3, a second terminal 60 that electrically connects the plurality of second electrode plates 30 to the board unit 3, and a holding member 70 that holds the first terminal 50 and the second terminal 60.

[0025] Hereinafter, the direction parallel to the central axis CL of the fluid property detection device 1 will be referred to as the axial direction of the fluid property detection device 1, and the direction perpendicular to this axial direction will be referred to as the radial direction of the fluid property detection device 1. In addition, the side on which the end cover 5 is disposed will be referred to as the base end side of the fluid property detection device 1, and the opposite side in the axial direction will be referred to as the tip side of the fluid property detection device 1.

[0026] The fluid property detection device 1 is attached by screw connection to a pipe P through which hydraulic oil flows, and detects the electrical properties of the hydraulic oil by a detection unit S arranged inside the pipe P. The detection unit S is constructed by stacking a plurality of first electrode plates 20 and a plurality of second electrode plates 30 alternately at predetermined intervals. The detection unit S protrudes from the housing 10 and is exposed in the hydraulic oil flowing through the pipe P.

[0027] 1, the housing 10 is made of, for example, a metal material, and includes, from the tip end to the base end, an attachment portion 11, a nut portion 12, a cover receiving portion 13, and an insertion portion 14.

[0028] The mounting portion 11 is cylindrical and has a male thread formed on its outer periphery. The male thread of the mounting portion 11 screws into a female thread formed on the inner periphery of a mounting hole P1 of the piping P. The fluid property detection device 1 is fixed to the piping P by the male thread of the mounting portion 11 screwing into the female thread of the mounting hole P1.

[0029] The nut portion 12 is formed to have a hexagonal prism shape. By rotating the nut portion 12 with a tool such as a wrench, the male thread of the mounting portion 11 and the female thread of the mounting hole 1a can be easily fastened to each other.

[0030] The cover receiving portion 13 is a flange portion that protrudes radially outward from the base end of the nut portion 12, and the tip surface of the cylindrical cover 4 abuts against it.

[0031] The insertion part 14 is made of a material such as metal or resin. The insertion part 14 is inserted into the inside of the cylindrical cover 4. The cylindrical cover 4 is fixed to the housing 10 by a screw or the like in a state in which the insertion part 14 is inserted until the tip surface of the cylindrical cover 4 abuts against the cover receiving part 13.

[0032] The end cover 5 closes the opening on the base end side of the cylindrical cover 4, and the end cover 5 is fixed to the cylindrical cover 4 by screws or the like.

[0033] 1, the board unit 3 has a circuit board 3a and a board holding member 3b that holds the circuit board 3a. The board unit 3 is accommodated in an accommodation space defined by a cylindrical cover 4, an end cover 5, a housing 10, and a mounting plate 40. The board unit 3 has the board holding member 3b fixed to the mounting plate 40 with screws or the like.

[0034] A detection circuit composed of a plurality of circuit elements is provided on the circuit board 3a. The circuit board 3a detects the voltage value or current value applied between the first electrode plate 20 and the second electrode plate 30, generates an electric signal, and outputs it to an external controller (not shown).

[0035] The holding member 70 is made of a material such as an insulating resin. The holding member 70 has a cylindrical main body 71, a guide portion 72 formed to protrude from an end face on the tip side of the main body 71 and having a smaller diameter than the main body 71, a first through hole 73 through which the first terminal 50 is inserted, and a second through hole 74 through which the second terminal 60 is inserted. The first through hole 73 and the second through hole 74 are provided at positions facing each other across the central axis CL.

[0036] The first terminal 50 and the second terminal 60 are formed of a conductive metal member. The first terminal 50 and the second terminal 60 are formed to have the same shape. The first terminal 50 and the second terminal 60 are held by the board holding member 3b or the mounting plate 40. The first terminal 50 and the second terminal 60 may be integrated with the holding member 70 by insert molding.

[0037] The base ends of the first terminal 50 and the second terminal 60 are electrically connected to a detection circuit (not shown) mounted on the circuit board 3a via wiring (not shown).

[0038] The first electrode plate 20 is electrically connected to the tip side of the first terminal 50 by solder or the like, and the second electrode plate 30 is electrically connected to the tip side of the second terminal 60 by solder or the like.

[0039] Next, the specific shapes of the first electrode plate 20 and the second electrode plate 30 will be described with reference to Fig. 3. The first electrode plate 20 and the second electrode plate 30 are formed to be identical to each other, that is, to be formed to be the same shape. For this reason, hereinafter, only the first electrode plate 20 will be mainly described, and the second electrode plate 30 will be appropriately omitted by adding a reference symbol in Fig. 3.

[0040] The first electrode plate 20 and the second electrode plate 30 are circular plates made of conductive metal. The first electrode plate 20 has an insertion hole 21 as a first insertion hole through which the first terminal 50 is inserted, a notch 22 as a first avoidance portion, and an insertion hole 23 through which the guide portion 72 of the holding member 70 is inserted. The second electrode plate 30 has an insertion hole 31 as a second insertion hole through which the second terminal 60 is inserted, a notch 32 as a second avoidance portion, and an insertion hole 33 through which the guide portion 72 of the holding member 70 is inserted.

[0041] The insertion hole 21 is formed penetrating the first electrode plate 20. The insertion hole 21 has an outer shape slightly larger than the first terminal 50. After the first terminal 50 is inserted into the insertion hole 21, it is electrically connected to the first electrode plate 20 by solder or the like.

[0042] The cutout portion 22 is formed by cutting out the first electrode plate 20 from the outer edge toward the center. The cutout portion 22 is formed to a size that avoids contact with the second terminal 60 when the first electrode plate 20 and the second electrode plate 30 are stacked. In the embodiment shown in FIG. 2, the cutout portion 22 is formed by cutting out the first electrode plate 20 in a U-shape, but this is not limited thereto. The cutout portion 22 may be formed by cutting out the outer edge of the first electrode plate 20 in a rectangular shape. Also, as shown in FIG. 4, instead of the cutout portion 22, a through hole 22a may be formed that is large enough to prevent contact with the second terminal 60 (see FIG. 3). In this case, the through hole 22a and the through hole 32a correspond to the first avoidance portion and the second avoidance portion in the claims, respectively.

[0043] The insertion hole 23 is formed so as to penetrate the first electrode plate 20 around the center of the first electrode plate 20. The insertion hole 23 has an outer diameter slightly larger than the outer diameter of the guide portion 72 of the holding member 70. As a result, when the guide portion 72 is inserted into the insertion hole 23, the radial movement of the first electrode plate 20 is restricted by the guide portion 72.

[0044] Next, the detection unit S will be described.

[0045] The detection unit S is configured by alternately stacking the first electrode plate 20 and the second electrode plate 30 at a predetermined interval, more specifically, by alternately stacking the first electrode plate 20 and the second electrode plate 30 in a state where they are inverted 180° from each other in the circumferential direction. In this embodiment, a spacer 80 for maintaining a predetermined interval is provided between the first electrode plate 20 and the plurality of second electrode plates 30. The spacer 80 is formed, for example, in a circular ring shape having an insertion hole 81 through which the guide portion 72 of the holding member 70 is inserted. The spacer 80 is formed of an insulating material.

[0046] When assembling the detection unit S, first, with the first terminal 50 and the second terminal 60 inserted into the holding member 70, the insertion hole 81 of the spacer 80 is inserted into the guide portion 72 of the holding member 70. Next, the first electrode plates 20 are stacked such that the insertion hole 21, the notch 22, and the insertion hole 23 of the first electrode plate 20 are inserted into the first terminal 50, the second terminal 60, and the guide portion 72 of the holding member 70, respectively.

[0047] Then, the insertion hole 81 of the spacer 80 is inserted into the guide portion 72 of the holding member 70. Next, the second electrode plates 30 are stacked such that the insertion hole 31, the cutout portion 32, and the insertion hole 33 of the second electrode plate 30 are inserted into the second terminal 60, the first terminal 50, and the guide portion 72 of the holding member 70, respectively. This process is repeated thereafter. In this way, the first electrode plates 20 and the second electrode plates 30 can be constructed by stacking them alternately at a predetermined interval.

[0048] When stacked, the stacked first electrode plates 20 and second electrode plates 30 are soldered to the first terminal 50 and the second terminal 60, respectively, for electrical connection. However, this is not limiting, and after stacking of all the first electrode plates 20 and second electrode plates 30 is completed, they may all be soldered at once by reflow soldering or the like.

[0049] In addition, the step of alternately stacking the first electrode plate 20 and the second electrode plate 30 while providing the spacer 80 between the first electrode plate 20 and the second electrode plate 30 in this assembly procedure corresponds to the "stacking step" in the claims. In addition, the step of electrically connecting the first electrode plate 20 to the first terminal 50 and the step of electrically connecting the second electrode plate 30 to the second terminal 60 correspond to the "first connection step" and the "second connection step" in the claims, respectively.

[0050] The board unit 3 and the first terminal 50, and the board unit 3 and the second terminal 60 are each electrically connected by soldering or the like. The process of electrically connecting the board unit 3 and the first terminal 50, and the process of electrically connecting the board unit 3 and the second terminal 60 correspond to a "third connecting process" in the claims.

[0051] Next, detection of a change in the property of the hydraulic oil by the fluid property detection device 1 will be described.

[0052] The dielectric constant of hydraulic oil generally increases as the hydraulic oil deteriorates. Therefore, when an AC voltage is applied from a controller (not shown) through the board unit 3, the first terminal 50, and the second terminal 60 while the detection unit S is immersed in hydraulic oil, the capacitance between the first electrode plate 20 and the second electrode plate 30 increases as the hydraulic oil deteriorates. Therefore, by periodically detecting the capacitance between the first electrode plate 20 and the second electrode plate 30 and comparing the detected capacitance with the capacitance detected in the past, it becomes possible to calculate the degree of deterioration of the hydraulic oil.

[0053] Specifically, every time the hydraulic device is driven, the capacitance between the first electrode plate 20 and the second electrode plate 30 is detected via the board unit 3, and the detected capacitance is stored in the controller. The controller compares the currently detected capacitance with the previously detected capacitance, and calculates the degree of deterioration of the hydraulic oil based on the rate of increase or decrease, etc.

[0054] In order to miniaturize the fluid property detection device 1, it is necessary to make the first electrode plate 20 and the second electrode plate 30 smaller. However, when the first electrode plate 20 and the second electrode plate 30 are made smaller, the capacitance decreases, in other words, the detection accuracy decreases. Therefore, in the fluid property detection device 1 of this embodiment, the first electrode plate 20 and the second electrode plate 30 are configured to be stacked in order to suppress the decrease in capacitance. This makes it possible to increase the total surface area of ​​each of the multiple first electrode plates 20 and the multiple second electrode plates 30, so that the capacitance can be increased compared to the size of the detection unit S. In other words, in the configuration in which the first electrode plate 20 and the second electrode plate 30 of this embodiment are stacked, even if the detection unit S is made smaller, the capacitance can be suppressed from decreasing. Therefore, according to the fluid property detection device 1, it is possible to miniaturize the device while suppressing the decrease in capacitance (decrease in detection accuracy). Furthermore, since both sides of the first electrode plate 20 and the second electrode plate 30 function as electrodes, the surface area can be increased. The capacitance can be increased compared to the size of the detection unit S.

[0055] In the above embodiment, an example has been described in which the properties of the hydraulic oil are detected based on the electrostatic capacitance between the first electrode plate 20 and the second electrode plate 30. However, this is not limited to this. A direct current may be applied to the first electrode plate 20 and the second electrode plate 30 to detect changes in the resistance value between the first electrode plate 20 and the second electrode plate 30 or changes in the current value flowing through the circuit, and the properties of the hydraulic oil may be determined based on the detection results.

[0056] In the above embodiment, the configuration including the spacer 80 has been described as an example, but the spacer 80 may be removed after assembling the fluid property detection device 1 (detection unit S), for example. The first electrode plate 20 and the second electrode plate 30 are fixed when they are soldered to the first terminal 50 and the second terminal 60, respectively. Therefore, for example, by forming the spacer 80 into a C-shape, the spacer 80 can be removed from the guide unit 72 after the first electrode plate 20 and the second electrode plate 30 are fixed. In this way, by removing the spacer 80, the capacitance can be increased accordingly.

[0057] Furthermore, if the guide portion 72 is configured to be detachable from the main body portion 71, for example, even if the spacer 80 has a circular shape, the spacer 80 can be removed by removing the guide portion 72. Note that the process of removing the spacer 80 after lamination of all the first electrode plates 20 and second electrode plates 30 is completed corresponds to a "spacer removal process."

[0058] In the above embodiment, the first electrode plate 20 and the second electrode plate 30 are described as being circular, but the shapes of the first electrode plate 20 and the second electrode plate 30 may be any shape, such as rectangular, polygonal, or elliptical.

[0059] In addition, in the embodiment shown in Figures 1 and 2, five first electrode plates 20 and five second electrode plates 30 are stacked, but the number of plates may be any number as long as there are at least two plates on one side and at least one plate on the other side.

[0060] In the embodiment shown in Figures 1 and 2, an example is described in which one first terminal 50 and one second terminal 60 are provided, but this is not limited to the above, and there may be two or more first terminals 50 and two or more second terminals 60.

[0061] In addition, the first electrode plate 20, the second electrode plate 30, the first terminal 50 and the second terminal 60 may first be stacked and soldered, and then the first terminal 50 and the second terminal 60 may be inserted into the first through hole 73 and the second through hole 74 of the holding member 70 to connect to the board unit 3.

[0062] The configuration, operation, and effects of the embodiment of the present invention configured as above will be described below.

[0063] The fluid property detection device 1 comprises a plate-shaped first electrode plate 20, a plate-shaped second electrode plate 30, and a substrate unit 3 (signal generating unit) that generates a signal corresponding to the properties of the fluid to be detected based on the electrical characteristics between the first electrode plate 20 and the second electrode plate 30, and the first electrode plate 20 and the second electrode plate 30 are stacked alternately at a predetermined interval.

[0064] In this configuration, the first electrode plate 20 and the second electrode plate 30 are alternately stacked at a predetermined interval, so that it is possible to ensure a sufficient total surface area for each of the first electrode plate 20 and the multiple second electrode plates 30. This makes it possible to miniaturize the fluid property detection device 1 while suppressing deterioration of the electrical characteristics (detection accuracy).

[0065] The fluid property detection device 1 further includes a spacer 80 that is provided between the adjacent first electrode plate 20 and second electrode plate 30 and maintains the distance between the adjacent first electrode plate 20 and second electrode plate 30.

[0066] In this configuration, the spacer 80 can reliably maintain the distance between the adjacent first electrode plate 20 and second electrode plate 30.

[0067] In the fluid property detection device 1, the first electrode plate 20 and the second electrode plate 30 have the same shape.

[0068] In this configuration, for example, when the first electrode plate 20 and the second electrode plate 30 are formed using a mold, these molds are common, so that mold costs can be suppressed. In addition, by using a common mold, the manufacturing method of the electrodes of the first electrode plate 20 and the second electrode plate 30 is also common, so that manufacturing costs can be reduced. Furthermore, inventory management is also made easier because the number of types of parts is reduced. In addition, the dimensional variation of the first electrode plate 20 and the second electrode plate 30 is stabilized, so that their electrostatic capacitances are stabilized.

[0069] The fluid property detection device 1 further includes a guide portion 72 through which the first electrode plate 20 and the second electrode plate 30 are inserted and which restricts movement of the first electrode plate 20 and the second electrode plate 30 in a direction perpendicular to the stacking direction of the first electrode plate 20 and the second electrode plate 30.

[0070] In this configuration, when stacking the first electrode plate 20 and the second electrode plate 30, the guide portion 72 can restrict the movement of the first electrode plate 20 and the second electrode plate 30 in a direction perpendicular to the stacking direction, improving the efficiency of assembly and shortening the assembly time. In addition, in this configuration, the first electrode plate 20 and the second electrode plate 30 are positioned by two points, the guide portion 72 and the first terminal 50 or the second terminal 60, so the cross-sectional area of ​​the positioning portion can be made smaller than when positioning is performed at one point. This allows the area related to detection of the first electrode plate 20 and the second electrode plate 30 to be increased.

[0071] The fluid property detection device 1 further includes a first terminal 50 electrically connecting the first electrode plate 20 and the substrate unit 3 (signal generating section), and a second terminal 60 electrically connecting the second electrode plate 30 and the substrate unit 3 (signal generating section). The first electrode plate 20 has an insertion hole 21 (first insertion hole) through which the first terminal 50 is inserted, and a first avoidance portion (notch 22, through hole 22a) formed to avoid contact with the second terminal 60 when the first electrode plate 20 and the second electrode plate 30 are stacked. The second electrode plate 30 has an insertion hole 31 (second insertion hole) through which the second terminal 60 is inserted, and a second avoidance portion (notch 32, through hole 32a) formed to avoid contact with the first terminal 50 when the first electrode plate 20 and the second electrode plate 30 are stacked.

[0072] This configuration can prevent the second terminal 60 from interfering with the first electrode plate 20, and can also prevent the first terminal 50 from interfering with the second electrode plate 30. Furthermore, this configuration can reduce the size of the fluid property detection device 1, since the first terminal 50 and the second terminal 60 do not protrude outside the first electrode plate 20 and the second electrode plate 30.

[0073] A manufacturing method of the fluid property detection device 1 for detecting the properties of a fluid to be detected includes a stacking process in which a plate-shaped first electrode plate 20 and a second electrode plate 30 having the same shape as the first electrode plate 20 are alternately stacked while maintaining a predetermined gap between them and being inverted 180° relative to each other in the circumferential direction; a first connection process in which the first electrode plate 20 is electrically connected to the first terminal 50; a second connection process in which the second electrode plate 30 is electrically connected to the second terminal 60; and a third connection process in which the first terminal 50 and the second terminal 60 are electrically connected to a substrate unit 3 (signal generating unit) that generates a signal corresponding to the properties of the fluid to be detected based on the electrical characteristics between the first electrode plate 20 and the second electrode plate 30.

[0074] In this configuration, the first electrode plate 20 and the second electrode plate 30 are alternately stacked at a predetermined interval, so that the total surface area of ​​each of the first electrode plate 20 and the second electrode plate 30 can be sufficiently secured. This makes it possible to miniaturize the fluid property detection device 1 while suppressing deterioration of the electrical characteristics (detection accuracy). Furthermore, in this configuration, the first electrode plate 20 and the second electrode plate 30 have the same shape, so that there is no risk of mistakenly picking up parts, as occurs when these have different shapes. Also, when the first electrode plate 20 and the second electrode plate 30 have different shapes, it is necessary to assemble them while checking the shapes and orientations of the parts. However, in the above configuration, it is only necessary to assemble the same parts while inverting them, so that assembly mistakes are less likely to occur. This improves assembly efficiency and makes it possible to reduce the number of assembly steps. Furthermore, in the case of automatic mounting, if there is a mistake in the placement of parts when feeding them into the mounting machine in the assembly process, an abnormality such as the stoppage of the mounting machine will occur. Therefore, by making the first electrode plate 20 and the second electrode plate 30 the same shape, the components can be standardized, eliminating the occurrence of mistakes in inserting components into the mounting machine, improving assembly efficiency, and enabling a reduction in assembly man-hours.

[0075] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments.

[0076] Also, a cover may be provided to cover the detection unit S. This cover is provided with a plurality of through holes that allow the flow of hydraulic oil. [Explanation of symbols]

[0077] REFERENCE SIGNS LIST 1 fluid property detection device, 2 detection unit, 3 board unit (signal generation section), 20 first electrode plate, 21 insertion hole (first insertion hole), 22 notch portion (first avoidance section), 22a through hole (first avoidance section), 30 second electrode plate, 31 insertion hole (second insertion hole), 32 notch portion (second avoidance section), 32a through hole (second avoidance section), 50 first terminal, 60 second terminal, 70 holding member, 71 main body section, 72 guide section, 80 spacer, S detection section

Claims

1. A fluid property detection device for detecting the property of a detection target fluid, comprising: A plate-shaped first electrode plate; A plate-shaped second electrode plate; a signal generating unit that generates a signal corresponding to the property of the fluid to be detected based on an electrical characteristic between the first electrode plate and the second electrode plate, A fluid property detection device, characterized in that the first electrode plates and the second electrode plates are alternately stacked at a predetermined interval.

2. The fluid property detection device according to claim 1, A fluid property detection device further comprising a spacer provided between adjacent first electrode plates and second electrode plates to maintain the gap between the adjacent first electrode plates and second electrode plates.

3. The fluid property detection device according to claim 1 or 2, 2. A fluid property detection device, wherein the first electrode plate and the second electrode plate are identical to each other.

4. The fluid property detection device according to claim 1 or 2, The first electrode plate and the second electrode plate each have an insertion hole, A fluid property detection device characterized in that it further comprises a guide portion that passes through the insertion hole of the first electrode plate and the insertion hole of the second electrode plate and restricts movement of the first electrode plate and the second electrode plate in a direction perpendicular to the stacking direction of the first electrode plate and the second electrode plate.

5. The fluid property detection device according to claim 1 or 2, a first terminal electrically connecting the first electrode plate and the signal generating unit; a second terminal electrically connecting the second electrode plate and the signal generating unit; The first electrode plate is a first insertion hole through which the first terminal is inserted; a first avoidance portion formed to avoid contact with the second terminal when the first electrode plate and the second electrode plate are stacked, The second electrode plate is a second insertion hole through which the second terminal is inserted; a second avoidance portion formed to avoid contact with the first terminal when the first electrode plate and the second electrode plate are stacked.

6. A method for manufacturing a fluid property detection device for detecting a property of a detection target fluid, comprising the steps of: a lamination step of alternately laminating a plate-shaped first electrode plate and a second electrode plate having the same shape as the first electrode plate while maintaining a predetermined interval and being rotated 180° from each other in a circumferential direction; a first connecting step of electrically connecting the first electrode plate to a first terminal; a second connecting step of electrically connecting the second electrode plate to a second terminal; A manufacturing method for a fluid property detection device, comprising: a signal generating unit that generates a signal corresponding to the properties of the fluid to be detected based on the electrical characteristics between the first electrode plate and the second electrode plate; and a third connection process that electrically connects the first terminal and the second terminal.

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