JP2018151363A - Fluid detector and fluid detection device including the same - Google Patents

Abstract

A working fluid is prevented from leaking outside through the inside of a fluid detector. A fluid detector (10) includes a detection unit (20), a power transmission unit (31), a power reception unit (27), a transmission unit (24), a reception unit (35), and a casing (40). Between the 1st accommodation hole 41 in which the power receiving part 27 and the transmission part 24 are accommodated, the 2nd accommodation hole 42 in which the power transmission part 31 and the receiving part 35 are accommodated, and between the 1st accommodation hole 41 and the 2nd accommodation hole 42 And a partition wall 43 that separates the first accommodation hole 41 and the second accommodation hole 42 from each other. [Selection] Figure 1

Description

  The present invention relates to a fluid detector for detecting a fluid state and a fluid detection device including the fluid detector.

  Patent Document 1 discloses a pressure detector that detects the pressure of the working fluid as a fluid detector that detects the state of the working fluid supplied to the fluid pressure device. Such a pressure detector generally has a detection unit that contacts the working fluid and an output unit that outputs the value detected by the detection unit to the outside.

JP 2006-28744 A

  In the pressure detector as described in Patent Document 1, the detection unit and the output unit are electrically connected by a lead wire or the like in the casing. When such a pressure detector is applied to a fluid pressure device to which a working fluid having a relatively high pressure is supplied, even if a seal member is provided in the casing, the working fluid that has flowed into the detection portion is separated from the casing. There is a possibility that the working fluid may leak to the outside through the inside of the fluid detector as a result of reaching the output section through a slight gap between the lead wire and the like.

  The present invention has been made in view of the above-described problems, and an object thereof is to prevent a working fluid from leaking through the inside of a fluid detector.

  In the first invention, the casing of the fluid detector includes a first housing part in which the detection unit, the power reception unit and the transmission unit are housed, a second housing part in which the power transmission unit and the reception unit are housed, and a first housing part. And a partition wall provided between the power storage unit and the second storage unit, and separating the first storage unit and the second storage unit, and transmitting and transmitting power between the power transmission unit and the power reception unit, Signal transmission between the two is performed wirelessly.

  In the first invention, the detection unit and the reception unit and the like are housed in the casing in a state of being physically separated by the partition wall, and transmit power from the power transmission unit to the power reception unit and from the transmission unit to the reception unit. Signal transmission is performed wirelessly. Accordingly, even if the detection target fluid flows into the first storage unit in which the detection unit or the like is stored, the detection target fluid is prevented from entering the second storage unit in which the power transmission unit or the like is stored by the partition wall.

  According to a second aspect of the present invention, the transmitter has a transmitter coil capable of magnetically transmitting a signal, and the receiver is arranged to face the transmitter coil across the partition wall and magnetically transmits the signal transmitted from the transmitter coil. The power receiving unit has a primary coil that generates a magnetic field according to the supplied current, the power receiving unit is disposed opposite the primary coil across the partition wall, and the primary coil is It has a secondary coil in which electromagnetic induction occurs according to the generated magnetic field, and a predetermined voltage is applied to the primary coil when detecting the state of the fluid to be detected.

  In the second invention, signal transmission between the transmission unit and the reception unit is performed magnetically, and power transmission between the power transmission unit and the power reception unit is performed magnetically. For this reason, even in the state of being physically isolated by the partition wall, it is possible to transmit a signal from the transmission unit to the reception unit and to transmit power from the power transmission unit to the power reception unit. Further, since a predetermined voltage is applied to the primary coil when detecting the state of the detection target fluid, it is possible to stably acquire a detection result corresponding to the state of the detection target fluid.

  The third invention is characterized in that the casing is made of metal, and each of the transmission coil, the reception coil, the primary coil, and the secondary coil is wound around a core having a higher magnetic permeability than the casing.

  In 3rd invention, each coil is each provided with the core which has a magnetic permeability higher than a casing. By providing the core having a relatively high magnetic permeability as described above, the magnetic flux density passing through the transmission coil and the reception coil and the magnetic flux density passing through the primary coil and the secondary coil can be increased. As a result, it is possible to improve the signal transmission efficiency from the transmission unit to the reception unit and the power transmission efficiency of power from the primary coil to the secondary coil.

  According to a fourth aspect of the present invention, a casing is formed of a resin, insert-molded in a state in which a transmission coil and a reception coil are arranged to face each other with a predetermined interval, and a primary coil and a secondary coil are predetermined. It is characterized by being insert-molded in a state of being opposed to each other with an interval of.

  In the fourth invention, the insert coil is formed in such a state that the transmitting coil and the receiving coil are arranged to face each other with a predetermined interval, and the primary coil and the secondary coil are arranged to face each other with a predetermined interval. Is done. For this reason, a partition is naturally formed between the transmission coil and the reception coil and between the primary coil and the secondary coil. Therefore, even if the detection target fluid flows into the first storage unit side in which the detection unit and the like are stored, the partition wall prevents the detection target fluid from entering the second storage unit side in which the power transmission unit and the like are stored.

  According to a fifth aspect of the present invention, the detection unit includes a pair of electrodes exposed to the detection target fluid, and the power received by the power reception unit is supplied to the pair of electrodes.

  In the fifth invention, the power received by the power receiving unit is supplied to the pair of electrodes exposed to the detection target fluid. For this reason, the signal received by the receiving unit and input to the signal processing unit has a value corresponding to the property of the detection target fluid interposed between the pair of electrodes. Thus, the fluid detector can detect the property of the detection target fluid interposed between the pair of electrodes.

  According to a sixth aspect of the invention, a fluid detection device including a fluid detector calculates a property value of a detection target fluid based on a signal received by the reception unit, and a property of the detection target fluid calculated by the calculation unit And a determination unit that determines a change in the property of the detection target fluid based on the value.

  In a sixth aspect, the fluid detection device includes a fluid detector, a calculation unit that calculates a property value of the detection target fluid, and a determination unit that determines a change in the property of the detection target fluid. For this reason, it becomes possible to grasp the change in the property of the detection target fluid by detecting the property of the detection target fluid with a fluid detector every predetermined time and calculating the property value of the detection target fluid in the calculation unit. Furthermore, the presence / absence of deterioration of the detection target fluid can be grasped by comparing the calculated property value of the detection target fluid with a predetermined threshold or the like in the determination unit.

  According to the present invention, it is possible to prevent the working fluid from leaking outside through the inside of the fluid detector.

It is the schematic which shows the structure of the fluid detector which concerns on embodiment of this invention. It is the schematic which shows the structure of the 1st modification of the fluid detector which concerns on embodiment of this invention. It is the schematic which shows the structure of the 2nd modification of the fluid detector which concerns on embodiment of this invention.

  Hereinafter, a fluid detector and a fluid detection device according to embodiments of the present invention will be described with reference to the drawings.

  For example, the fluid detector is attached directly to a fluid pressure device such as a hydraulic cylinder that drives the hydraulic oil as the hydraulic fluid, or to a pipe connected to the hydraulic cylinder or the like. It detects the state of. The detection target of the fluid detector is not limited to hydraulic oil, and may be various liquids and gases such as lubricating oil, cutting oil, fuel, solvent, and chemicals. In the following, a description will be given of a case where the fluid detection device is an oil property detection device 100 that detects the property of hydraulic oil, and the fluid detector is used as the oil sensor 10 that is disposed facing the hydraulic oil in the oil property detection device 100. To do.

  The oil property detection device 100 is attached to a pipe 1 through which hydraulic oil flows, and includes an oil sensor 10 as a fluid detector that detects the property of the hydraulic oil, and instructs the oil sensor 10 to detect the property of the hydraulic oil. And a control unit 50 to which a detection value detected by the oil sensor 10 is input.

  As shown in FIG. 1, the oil sensor 10 is supplied to the casing 40 coupled to the holder portion 2 formed in the pipe 1, the detection unit 20 disposed facing the hydraulic oil, and the detection unit 20. A power transmission unit 31 that wirelessly transmits power, a power reception unit 27 that receives the power transmitted wirelessly from the power transmission unit 31 and supplies the received power to the detection unit 20, and a current that flows through the detection unit 20 A transmission unit 24 that wirelessly transmits a signal, a reception unit 35 that receives a signal wirelessly transmitted from the transmission unit 24, and a signal processing unit 39 to which the signal received by the reception unit 35 is input.

  The casing 40 is a columnar member formed of a steel material having a relatively low magnetic permeability such as austenitic stainless steel or aluminum alloy. The casing 40 accommodates the detection unit 20, the transmission unit 24, and the power reception unit 27 on the pipe 1 side. A first accommodation hole 41 is formed as one accommodation portion, and a second accommodation hole 42 as a second accommodation portion that accommodates the power transmission unit 31, the reception unit 35, and the signal processing unit 39 is formed on the side opposite to the pipe 1. It is formed.

  Each of the first accommodation hole 41 and the second accommodation hole 42 is a bottomed hole, and a partition wall 43 is provided between them. That is, the space in the first accommodation hole 41 and the space in the second accommodation hole 42 are physically separated by the partition wall 43.

  A gasket 3 is provided between the casing 40 and the holder portion 2, and the gasket 3 prevents hydraulic fluid from leaking outside through a gap between the holder portion 2 and the casing 40. The holder part 2 and the casing 40 are screwed together via a screw part (not shown). In addition, the coupling | bonding method of the holder part 2 and the casing 40 is not limited to screwing, A fitting may be sufficient and the coupling | bonding using fastening members, such as a volt | bolt, may be sufficient.

  The detection unit 20 has a pair of electrodes 21 exposed to the hydraulic oil. The pair of electrodes 21 is composed of two flat plate members arranged to face each other with a predetermined gap, and a gap through which hydraulic oil can enter is formed between the pair of electrodes 21. In the oil property detection device 100, the property of the hydraulic oil interposed in the gap between the pair of electrodes 21 is detected. One of the pair of electrodes 21 is connected to the power reception unit 27 via the wiring 22, and the other of the pair of electrodes 21 is connected to the transmission unit 24 via the wiring 23.

  The power transmission unit 31 includes an excitation circuit 32 mounted on the substrate 30 disposed in the second accommodation hole 42 and a primary coil 33 connected to the excitation circuit 32. The excitation circuit 32 is configured to apply a sine wave or rectangular wave voltage to the primary coil 33 in accordance with a command from the control unit 50, and to cause a current to flow through the primary coil 33. The primary coil 33 is a coil in which a conductive wire is wound around a U-shaped core 34, and is disposed in the second accommodation hole 42 so that the end of the core 34 contacts the partition wall 43.

  The receiving unit 35 includes a secondary coil 28 that is disposed to face the primary coil 33 with the partition wall 43 interposed therebetween. The secondary coil 28 is a coil in which a conducting wire is wound around a U-shaped core 29, and is disposed in the first accommodation hole 41 so that the end of the core 29 contacts the partition wall 43. The cores 29 and 34 are made of a ferrous steel material having a higher permeability than the partition wall 43.

  As described above, the primary coil 33 and the secondary coil 28 are arranged with the partition wall 43 interposed therebetween so that the ends of the cores 29 and 34 face each other. For this reason, when a current is supplied from the excitation circuit 32 to the primary coil 33 and a magnetic field is generated around the primary coil 33, a predetermined induced electromotive force is generated in the secondary coil 28 disposed opposite to the primary coil 33, A current is supplied to the detection unit 20. That is, the primary coil 33 and the secondary coil 28 constitute a transformer. The magnitude of the voltage between the pair of electrodes 21 changes transiently according to the resistance value and the capacitance value of the hydraulic oil interposed between the pair of electrodes 21.

  Further, as described above, the primary coil 33 and the secondary coil 28 are wound around the cores 29 and 34 formed of a material having a higher magnetic permeability than the partition wall 43. For this reason, compared with the case without the cores 29 and 34, the magnetic flux density which passes the primary coil 33 and the secondary coil 28 becomes large, and even if it reduces the electric current supplied to the primary coil 33, it generate | occur | produces in the secondary coil 28. It is possible to increase the induced electromotive force.

  Further, as shown in FIG. 1, the core 34 of the primary coil 33 and the core 29 of the secondary coil 28 face each other with a partition wall 43 made of a material having a relatively low permeability interposed therebetween. Since it is arranged at, it appears to be in a ring-like state. For this reason, a magnetic field is generated so as to pass through the inside of the primary coil 33 and the secondary coil 28 along the cores 29 and 34, and the leakage of the magnetic field is reduced. As a result, it is possible to increase the electromotive force generated in the secondary coil 28 even if the current supplied to the primary coil 33 is reduced.

  The transmission unit 24 includes a transmission coil 25 connected in series with the pair of electrodes 21 and the secondary coil 28. The transmission coil 25 is a coil in which a conducting wire is wound around a U-shaped core 26, and is disposed in the first accommodation hole 41 so that the end of the core 26 contacts the partition wall 43.

  The receiving unit 35 includes a receiving circuit 36 mounted on the substrate 30 and a receiving coil 37 connected to the receiving circuit 36. The receiving circuit 36 detects an induced electromotive force generated in the receiving coil 37 in response to a change in the magnetic field in the transmitting coil 25. When the electromotive force is small, it is preferable to provide an operational amplifier in the receiving circuit 36 in order to improve detection accuracy. The receiving coil 37 is a coil in which a conducting wire is wound around a U-shaped core 38, and is disposed in the second accommodation hole 42 so that the end of the core 38 contacts the partition wall 43. The cores 26 and 38 are made of a ferrous steel material having a higher permeability than the partition wall 43.

  As described above, the transmission coil 25 and the reception coil 37 are arranged with the partition wall 43 interposed therebetween so that the ends of the cores 26 and 38 face each other. For this reason, when the current flowing through the transmission coil 25, that is, the magnitude of the current flowing between the pair of electrodes 21 changes, the magnitude of the current changes in the reception coil 37 disposed facing the transmission coil 25. A corresponding induced electromotive force is generated. Therefore, by detecting the induced electromotive force generated in the receiving coil 37 by the receiving circuit 36, it is possible to grasp the change in the magnitude of the current flowing between the pair of electrodes 21.

  Further, as described above, the transmission coil 25 and the reception coil 37 are wound around the cores 26 and 38 formed of a material having a higher magnetic permeability than the partition wall 43. For this reason, compared with the case where there is no core 26,38, the magnetic flux density which passes the transmission coil 25 and the receiving coil 37 becomes large. Therefore, even if the current flowing through the transmission coil 25 is small, the induced electromotive force generated in the reception coil 37 is large, and the signal transmission efficiency from the transmission unit 24 to the reception unit 35 is improved.

  Further, as shown in FIG. 1, the core 26 of the transmission coil 25 and the core 38 of the reception coil 37 are in a state where the end portions face each other with a partition wall 43 formed of a material having a relatively low permeability. Since it is arranged, it appears to be connected in an annular shape. For this reason, the magnetic field is generated so as to pass through the inside of the transmission coil 25 and the reception coil 37 along the cores 26 and 38, and the leakage of the magnetic field is reduced. Therefore, even if the current flowing through the transmission coil 25 is small, the electromotive force generated in the reception coil 37 is large, and the signal transmission efficiency from the transmission unit 24 to the reception unit 35 is improved.

  The signal processing unit 39 is a circuit mounted on the substrate 30 together with the excitation circuit 32 and the reception circuit 36, and includes circuit elements such as an A / D converter (not shown). The signal processing unit 39 includes an induced electromotive force in the receiving coil 37 detected by the receiving circuit 36, that is, a current value flowing between the pair of electrodes 21, and a current value supplied to the primary coil 33 by the excitation circuit 32, that is, Then, the induced electromotive force in the secondary coil 28 is input, converted from an analog signal to a digital signal in the A / D converter, and then output to the control unit 50.

  The detection unit 20, the transmission unit 24, and the power reception unit 27 configured as described above are insert-molded in the first accommodation hole 41 in a state where only a part of the pair of electrodes 21 protrudes to the outside, so that the casing 40 is Fixed. Further, the power transmission unit 31, the reception unit 35, and the signal processing unit 39 having the above-described configuration are fixed to the casing 40 by being insert-molded into the second accommodation hole 42 together with the substrate 30.

  The control unit 50 is a microcomputer, and stores a calculation unit 51 that calculates conductivity, which is a property value of hydraulic oil, based on a detection value detected by the oil sensor 10, and a conductivity calculated by the calculation unit 51. The storage unit 52 that can be stored, an auxiliary storage unit such as a ROM or a RAM (not shown) that stores programs used in the calculation unit 51, the conductivity of hydraulic fluid calculated by the calculation unit 51 and the storage unit 52 It has the determination part 53 which compares the past electrical conductivity, and determines the change state of the property of hydraulic fluid, and the input / output interface (I / O interface) which is not shown in figure. The calculation unit 51 and the determination unit 53 are so-called central processing units (CPU), and the storage unit 52 is a rewritable nonvolatile memory such as an EEPROM. The control unit 50 may be provided outside the oil sensor 10 or may be disposed in the second accommodation hole 42 of the oil sensor 10 together with the signal processing unit 39.

  Next, a method for detecting the property of hydraulic oil by the oil property detection device 100 having the above-described configuration will be described.

  First, the electrical characteristics of the hydraulic oil interposed between the pair of electrodes 21 are detected by the oil sensor 10.

  The electrical characteristics of the hydraulic oil are detected by applying a voltage between the pair of electrodes 21 of the detection unit 20. Specifically, first, a voltage having a predetermined waveform is applied from the excitation circuit 32 to the primary coil 33 to generate a magnetic field around the primary coil 33. When a magnetic field is generated around the primary coil 33, an induced electromotive force is generated in the secondary coil 28 disposed to face the primary coil 33, and a pair of wires connected to the secondary coil 28 via the wirings 22 and 23. A voltage is applied between the electrodes 21. That is, the temporal change in the voltage value applied to the primary coil 33 from the excitation circuit 32 corresponds to the temporal change in the induced electromotive force in the secondary coil 28, that is, the voltage value applied between the pair of electrodes 21. . As described above, when detecting the state of the hydraulic fluid that is the detection target fluid interposed between the pair of electrodes 21, a voltage having a predetermined waveform is applied from the excitation circuit 32 to the primary coil 33. A voltage having a predetermined waveform is applied between 21. The voltage applied between the pair of electrodes 21 may be a sinusoidal AC voltage, or a rectangular wave, a triangular wave, or a sawtooth wave AC voltage.

  Here, since the hydraulic oil has a specific resistance value and a capacitance value, the pair of electrodes 21 can be regarded as a circuit in which a capacitor and a resistor are connected in parallel. For this reason, after a predetermined voltage is applied between the pair of electrodes 21, the magnitude of the voltage between the pair of electrodes 21 depends on the resistance value and the capacitance value of the hydraulic oil existing between the pair of electrodes 21. Accordingly, the applied voltage gradually approaches the applied voltage with a predetermined time delay. On the other hand, the current flowing through the wirings 22 and 23 connecting the pair of electrodes 21 gradually decreases as charges are accumulated in the pair of electrodes 21.

  Then, the temporal change in the magnitude of the current flowing through the wirings 22 and 23 connecting the pair of electrodes 21 is transmitted as a signal to the reception circuit 36 via the transmission coil 25 and the reception coil 37. Specifically, when a current flowing through the wirings 22 and 23 flows through the transmission coil 25, a magnetic field is generated around the transmission coil 25. When a magnetic field is generated around the transmission coil 25 in this manner, an induced electromotive force is generated in the reception coil 37 disposed opposite to the transmission coil 25, and the induced electromotive force generated in the reception coil 37 is detected by the reception circuit 36. Is done.

  The temporal change in the voltage value detected in the receiving circuit 36 indicates the temporal change in the current value flowing through the wirings 22 and 23 connecting the pair of electrodes 21. The temporal change in the voltage value is Along with the temporal change of the current value supplied to the primary coil 33 in the excitation circuit 32, it is output to the control unit 50 as an output value of the oil sensor 10 through the signal processing unit 39.

  Subsequently, in the control unit 50, calculation of the property value of the hydraulic oil and determination of deterioration of the hydraulic oil are performed.

  In the control unit 50, the pair of electrodes 21 is calculated based on the temporal change in the voltage value detected by the receiving circuit 36 in the calculation unit 51 and the temporal change in the voltage value applied from the excitation circuit 32 to the primary coil 33. The impedance between them is calculated, and the phase difference between the current flowing between the pair of electrodes 21 and the voltage applied between the pair of electrodes 21 is calculated. In the calculation unit 51, the resistance value and the capacitance value between the pair of electrodes 21 are calculated from the calculated impedance and phase difference using a known calculation formula, and based on the shape of the pair of electrodes 21. From the relational expression, the electrical conductivity and dielectric constant of the hydraulic oil are derived. The property value such as conductivity calculated by the calculation unit 51 is stored in the storage unit 52.

  Then, the determination unit 53 compares the conductivity calculated by the calculation unit 51 with the past conductivity stored in the storage unit 52 or the reference conductivity stored in the storage unit 52, and the hydraulic oil It is determined whether or not the battery has deteriorated. Specifically, for example, if the difference between the conductivity calculated by the calculation unit 51 and the past conductivity stored in the storage unit 52 exceeds a predetermined threshold, it is determined that the hydraulic oil has deteriorated. If the difference between the conductivity calculated by the calculation unit 51 and the reference conductivity stored in the storage unit 52 exceeds a predetermined threshold value, it is determined that the hydraulic oil has deteriorated. If the determination unit 53 determines that the hydraulic oil has deteriorated, the operator is notified that the hydraulic oil has deteriorated via a warning lamp (not shown) or the like.

  In general, the conductivity and dielectric constant of oil increase due to deterioration of the oil and contamination of the oil. From this, it is possible to determine the degree of deterioration of the hydraulic oil by periodically calculating the resistance value or the capacitance value between the pair of electrodes 21 and comparing the calculated value with a value calculated in the past. Is possible. It should be noted that the detection of the property of the hydraulic oil by the oil sensor 10 may be performed all the time, or may be performed only when instructed by the control unit 50, for example, when the hydraulic device is started or stopped.

  In calculating the impedance between the pair of electrodes 21, an effective value or a maximum value of the detected value may be used instead of the temporal change of the detected value. In this case, the voltage applied between the pair of electrodes 21 is a pulse voltage instead of the AC voltage, and the degree of deterioration of the hydraulic fluid can be determined from the calculated change in impedance.

  The property value of the hydraulic fluid such as conductivity stored in the storage unit 52 and the determination result in the determination unit 53 are transmitted to a hydraulic oil monitoring server or the like disposed in a remote place via a communication unit (not shown). May be. In this case, it becomes possible to grasp the degree of deterioration of the hydraulic fluid of the hydraulic device at a remote place, and it is possible to instruct replacement of hydraulic fluid as necessary.

  As described above, in the oil sensor 10 having the above-described configuration, when the property of the hydraulic oil is detected, power transmission from the power transmission unit 31 to the power reception unit 27 and transmission of a signal from the transmission unit 24 to the reception unit 35 are performed wirelessly. Done. Each element constituting the oil sensor 10 is housed in the casing 40 in a state of being physically separated by the partition wall 43. Therefore, even if the hydraulic oil flows into the first accommodation hole 41 in which the detection unit 20 and the like are accommodated, the hydraulic oil enters the second accommodation hole 42 in which the power transmission unit 31 and the like are accommodated by the partition wall 43. Be blocked. Even if the first accommodation hole 41 in which the detection unit 20 or the like is accommodated is exposed to high-pressure hydraulic oil, the pressure of the hydraulic oil is blocked by the partition wall 43 so that the first accommodation hole 41 is accommodated in the second accommodation hole 42. The hydraulic oil pressure is prevented from reaching the power transmission unit 31 and the like. As a result, it is possible to reliably prevent the hydraulic oil from leaking outside through the inside of the oil sensor 10.

  In particular, in a hydraulic device such as a hydraulic cylinder driven by a relatively high pressure hydraulic oil, if the hydraulic oil leaks, the hydraulic oil pressure decreases, causing a malfunction of the hydraulic device, or the hydraulic oil leaking to the outside. The environment in which the device is used will be contaminated. However, by using the oil sensor 10 having the above-described configuration, it is possible to prevent hydraulic oil from leaking outside through the inside of the oil sensor 10, so that malfunction of the hydraulic device and environmental pollution can be avoided. In other words, the oil sensor 10 having the above-described configuration can be applied to a hydraulic device that is driven by hydraulic oil having a higher pressure because the hydraulic oil does not leak to the outside through the inside.

  Further, in the oil sensor 10 having the above-described configuration, the space in which the detection unit 20 and the like are accommodated and the space in which the power transmission unit 31 and the like are accommodated are physically separated by the partition wall 43, and thus a seal member is provided between them. Or a structure for preventing leakage of hydraulic oil through the oil sensor 10 is not required.

  According to the above embodiment, there exist the effects shown below.

  In the oil sensor 10 configured as described above, the detection unit 20 and the reception unit 35 and the like are housed in the casing 40 in a state of being physically separated by the partition wall 43, and power is transmitted from the power transmission unit 31 to the power reception unit 27. The transmission of the signal from the transmission unit 24 to the reception unit 35 is performed wirelessly. Therefore, even if the hydraulic oil flows into the first accommodation hole 41 in which the detection unit 20 and the like are accommodated, the hydraulic oil enters the second accommodation hole 42 in which the power transmission unit 31 and the like are accommodated by the partition wall 43. Be blocked. Even if the first accommodation hole 41 in which the detection unit 20 or the like is accommodated is exposed to high-pressure hydraulic oil, the pressure of the hydraulic oil is blocked by the partition wall 43 so that the first accommodation hole 41 is accommodated in the second accommodation hole 42. The hydraulic oil pressure is prevented from reaching the power transmission unit 31 and the like. As a result, it is possible to reliably prevent the hydraulic oil from leaking outside through the inside of the oil sensor 10.

  In the oil sensor 10 having the above configuration, the casing 40 is formed of a metal having a relatively low magnetic permeability. Instead, as shown in the first modification example in FIG. It is good also as a structure made from hard resin with very low magnetic permeability, and insert-molding the detection part 20 grade | etc.,.

  Specifically, the transmission coil 25 and the reception coil 37 are insert-molded in a state of being opposed to each other with a predetermined interval L, and the primary coil 33 and the secondary coil 28 have a predetermined interval L. Insert molding is performed in a state of being opposed to each other. That is, the partition wall 43 having a width L is formed between the transmission coil 25 and the reception coil 37 and between the primary coil 33 and the secondary coil 28 with resin. The distance L between the transmission coil 25 and the reception coil 37 and the distance L between the primary coil 33 and the secondary coil 28 may be different sizes.

  And also in this case, the 1st accommodating part in which the detection part 20, the power receiving part 27, and the transmission part 24 are accommodated, and the power transmission part 31, the receiving part 35, and the signal processing part 39 are accommodated similarly to the said embodiment. The partition wall 43 is provided between the second housing portion and the hydraulic oil is prevented from entering the second housing portion. As a result, the hydraulic oil leaks to the outside through the oil sensor 10. Can be reliably prevented.

  In this case, since the casing 40 is formed of a resin having a very low magnetic permeability, the casing 40 hardly affects the magnetic field generated in the transmission coil 25 and the primary coil 33. For this reason, the transmission of the signal from the transmission unit 24 to the reception unit 35 can be performed more efficiently, and the transmission of the power from the power transmission unit 31 to the power reception unit 27 can be performed more efficiently.

  When the casing 40 is made of resin, a metal cylinder 44 that covers the outer peripheral surface may be provided for reinforcement. When such a metal tube 44 is provided, noise from the outside is blocked by the shielding effect, so that signal transmission efficiency from the transmission unit 24 to the reception unit 35 and power transmission from the power transmission unit 31 to the power reception unit 27 are performed. Efficiency can be improved.

  Moreover, in the said embodiment, transmission of the signal between the transmission part 24 and the receiving part 35 is performed magnetically by the two coils arrange | positioned facing each other. The transmission of the signal between the transmission unit 24 and the reception unit 35 is not limited to this, and may be performed in any format as long as it is performed wirelessly, for example, by radio waves.

  Further, the fluid detector is not limited to the oil sensor 10, and as shown in the second modified example of FIG. 3, a temperature sensor 110 that detects the temperature of the hydraulic oil or a pressure sensor 210 that detects the pressure of the hydraulic oil. There may be.

  As shown in FIG. 3, instead of the pair of electrodes 21, the temperature sensor 110 is provided in parallel with a resistor 21a whose resistance value changes in accordance with the temperature of the hydraulic oil and a known electrostatic capacitance value. Capacitor 21b. For this reason, similarly to the oil sensor 10 described above, by detecting a temporal change in the voltage at both ends of the resistor 21a and the capacitor 21b after a predetermined voltage is applied, a change in the resistance value of the resistor 21a, that is, It is possible to grasp changes in the temperature of hydraulic oil.

  As shown in FIG. 3, the pressure sensor 210 is replaced with a resistor 21 a that changes its resistance value by being deformed by the pressure of hydraulic oil, instead of the pair of electrodes 21, and a resistor 21 a that has a known capacitance value. And a capacitor 21b provided in parallel. For this reason, similarly to the oil sensor 10 described above, by detecting a temporal change in the voltage at both ends of the resistor 21a and the capacitor 21b after a predetermined voltage is applied, a change in the resistance value of the resistor 21a, that is, It is possible to grasp changes in hydraulic oil pressure. In addition, the part which detects a pressure in the pressure sensor 210 is not limited to the resistance 21a, For example, the capacitor | condenser etc. from which the space | interval between a pair of electrodes changes with pressure may be sufficient.

  Thus, even if the fluid detector is the temperature sensor 110 that detects the temperature of the hydraulic oil or the pressure sensor 210 that detects the pressure of the hydraulic oil, the detection unit 20 and the reception unit 35 and the like are separated from each other. The power is transmitted from the power transmission unit 31 to the power reception unit 27 and the signal is transmitted from the transmission unit 24 to the reception unit 35 wirelessly. Therefore, even if the hydraulic oil flows into the first accommodation hole 41 in which the detection unit 20 and the like are accommodated, the hydraulic oil enters the second accommodation hole 42 in which the power transmission unit 31 and the like are accommodated by the partition wall 43. Be blocked. As a result, it is possible to reliably prevent the hydraulic oil from leaking outside through the temperature sensor 110 and the pressure sensor 210.

  The configuration, operation, and effect of the embodiment of the present invention configured as described above will be described together.

  The fluid detectors 10, 110, and 210 are wirelessly transmitted from the detection unit 20 disposed facing the hydraulic oil, the power transmission unit 31 that wirelessly transmits power supplied to the detection unit 20, and the power transmission unit 31. The power receiving unit 27 that receives power and supplies the received power to the detection unit 20, the transmission unit 24 that wirelessly transmits a signal corresponding to the current flowing through the detection unit 20, and the wireless transmission from the transmission unit 24 A reception unit 35 that receives a signal, a signal processing unit 39 that receives a signal received by the reception unit 35, a detection unit 20, a power transmission unit 31, a power reception unit 27, a transmission unit 24, a reception unit 35, and a signal processing unit A casing 40 in which the housing 39 is housed. The casing 40 includes a first housing hole 41 in which the detection unit 20, the power reception unit 27 and the transmission unit 24 are housed, a power transmission unit 31, a reception unit 35, and a signal processing unit 39. A second receiving hole 42 for receiving The first accommodation hole 41 is provided between the second accommodation hole 42 has a partition wall 43 which isolates the first accommodation hole 41 and a second receiving hole 42, the.

  In this configuration, the detection unit 20 and the reception unit 35 and the like are housed in the casing 40 in a state of being physically separated by the partition wall 43, and transmit and receive power from the power transmission unit 31 to the power reception unit 27. The signal is transmitted from the receiver to the receiver 35 wirelessly. Therefore, even if the hydraulic oil flows into the first accommodation hole 41 in which the detection unit 20 and the like are accommodated, the hydraulic oil enters the second accommodation hole 42 in which the power transmission unit 31 and the like are accommodated by the partition wall 43. Be blocked. Even if the first accommodation hole 41 in which the detection unit 20 or the like is accommodated is exposed to high-pressure hydraulic oil, the pressure of the hydraulic oil is blocked by the partition wall 43 so that the first accommodation hole 41 is accommodated in the second accommodation hole 42. The hydraulic oil pressure is prevented from reaching the power transmission unit 31 and the like. As a result, it is possible to reliably prevent the hydraulic oil from leaking outside through the inside of the oil sensor 10.

  The transmission unit 24 includes a transmission coil 25 capable of magnetically transmitting a signal, and the reception unit 35 is disposed to face the transmission coil 25 with the partition wall 43 interposed therebetween, and a signal transmitted from the transmission coil 25. The power transmission unit 31 includes a primary coil 33 that generates a magnetic field according to the supplied current, and the power reception unit 27 includes the primary coil 33 with the partition wall 43 interposed therebetween. The primary coil 33 has a secondary coil 28 that is arranged oppositely and generates electromagnetic induction according to the magnetic field generated by the primary coil 33. When detecting the state of the hydraulic fluid that is the detection target fluid, the primary coil 33 has a predetermined value. Is applied.

  In this configuration, signal transmission between the transmission unit 24 and the reception unit 35 is magnetically performed by the transmission coil 25 and the reception coil 37, and power transmission between the power transmission unit 31 and the power reception unit 27 is primary. Magnetically performed by the coil 33 and the secondary coil 28. For this reason, even if the transmission unit 24 and the reception unit 35 are physically separated by the partition wall 43, the signal can be reliably transmitted from the transmission unit 24 to the reception unit 35, and the power transmission unit 31. Even when the power receiving unit 27 and the power receiving unit 27 are physically separated by the partition wall 43, the power can be reliably transmitted from the power transmitting unit 31 to the power receiving unit 27. In addition, since a predetermined voltage is applied to the primary coil 33 when detecting the state of the hydraulic fluid that is the detection target fluid, it is possible to stably acquire a detection result corresponding to the state of the hydraulic oil. Become.

  The casing 40 is made of metal, and the transmission coil 25, the reception coil 37, the primary coil 33, and the secondary coil 28 are wound around the cores 26, 29, 34, 38 having higher magnetic permeability than the casing 40, respectively. Has been.

  In this configuration, each coil 25, 28, 33, 37 includes a core 26, 29, 34, 38 having a higher magnetic permeability than the casing 40. When the metal casing 40 exists between the coils, the signal transmission efficiency between the coils is lowered, but the cores 26, 29, 34, and 38 having relatively high permeability are provided, so that the transmission coil 25 and the reception coil are received. The magnetic flux density passing through the coil 37 and the magnetic flux density passing through the primary coil 33 and the secondary coil 28 are increased. For this reason, even if the current flowing through the transmission coil 25 and the primary coil 33 is small, the induced electromotive force generated in the reception coil 37 and the secondary coil 28 increases, and as a result, the signal is transmitted from the transmission unit 24 to the reception unit 35. Efficiency and power transmission efficiency of power from the primary coil 33 to the secondary coil 28 can be improved. Moreover, in this structure, since the casing 40 which accommodates the detection part 20 grade | etc., Is metal, the noise from the outside is interrupted | blocked by the shielding effect. As a result, the detection accuracy in the detection unit 20 is improved, and the transmission efficiency of the signal from the transmission unit 24 to the reception unit 35 and the power transmission efficiency of the power from the power transmission unit 31 to the power reception unit 27 can be improved.

  The casing 40 is made of resin, and the transmission coil 25 and the reception coil 37 are insert-molded in a state of being opposed to each other with a predetermined distance L. The primary coil 33 and the secondary coil 28 are The insert molding is performed in a state of being opposed to each other with a predetermined interval L therebetween.

  In this configuration, the transmission coil 25 and the reception coil 37 are arranged to face each other with a predetermined interval L, and the primary coil 33 and the secondary coil 28 are arranged to face each other with a predetermined interval L. Each is insert molded. For this reason, resin-made partition walls 43 are naturally formed between the transmission coil 25 and the reception coil 37 and between the primary coil 33 and the secondary coil 28 during insert molding. Therefore, even if the hydraulic oil flows into the first housing part side in which the detection unit 20 or the like is housed, the power transmission unit 31 or the like is housed by providing the resin partition wall 43 formed integrally with the casing 40. It is possible to prevent the hydraulic oil from entering the second storage portion.

  Further, since the permeability of the resin is extremely low, the resin does not affect the magnetic field generated around the transmission coil 25 and the primary coil 33. Therefore, transmission of signals from the transmission unit 24 to the reception unit 35 can be performed more efficiently, and transmission of power from the power transmission unit 31 to the power reception unit 27 can be performed more efficiently.

  Further, the detection unit 20 includes a pair of electrodes 21 exposed to the hydraulic oil, and the power received by the power reception unit 27 is supplied to the pair of electrodes 21.

  In this configuration, the power received by the power receiving unit 27 is supplied to the pair of electrodes 21 exposed to the hydraulic oil. For this reason, the signal received by the receiving unit 35 and input to the signal processing unit 39 has a value corresponding to the property of the hydraulic oil interposed between the pair of electrodes 21. Thus, the fluid detector 10 can detect the property of the hydraulic oil interposed between the pair of electrodes 21.

  The fluid detection device 100 including the fluid detector 10 having the above-described configuration includes a calculation unit 51 that calculates the property value of the hydraulic oil based on the signal received by the reception unit 35, and the hydraulic oil calculated by the calculation unit 51. And a determination unit 53 that determines a change in the property of the hydraulic oil based on the property value.

  In this configuration, the fluid detection device 100 includes the fluid detector 10, and includes a calculation unit 51 that calculates the property value of the hydraulic oil, and a determination unit 53 that determines a change in the property of the hydraulic oil. For this reason, it is possible to detect the change in the property of the hydraulic oil by detecting the property of the hydraulic oil by the fluid detector 10 every predetermined time and calculating the property value of the hydraulic oil by the calculation unit 51. Furthermore, it is possible to grasp the presence or absence of deterioration of the hydraulic oil by comparing the calculated property value of the hydraulic oil with a predetermined threshold or the like in the determination unit 53.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  DESCRIPTION OF SYMBOLS 100 ... Oil property detection apparatus (fluid detection apparatus), 10 ... Oil sensor (fluid detector), 20 ... Detection part, 21 ... Pair of electrodes, 24 ... Transmission part, 25. ..Transmission coil, 26, 29, 34, 38 ... core, 27 ... power receiving unit, 28 ... secondary coil, 31 ... power transmission unit, 33 ... primary coil, 35 ... Receiving part, 37 ... receiving coil, 39 ... signal processing part, 40 ... casing, 41 ... first receiving hole (first receiving part), 42 ... second receiving hole (second (Accommodating part), 43 ... partition wall, 50 ... control part, 51 ... calculation part, 52 ... storage part, 53 ... determination part, 110 ... temperature sensor (fluid detector), 210 ... Pressure sensor (fluid detector)

Claims (6)

A fluid detector for detecting a state of a detection target fluid,
A detection unit disposed facing the detection target fluid;
A power transmission unit that wirelessly transmits power supplied to the detection unit;
A power receiving unit that receives the power transmitted wirelessly from the power transmission unit, and that supplies the received power to the detection unit;
A transmitter that wirelessly transmits a signal corresponding to the current flowing through the detector;
A receiver that receives the signal transmitted from the transmitter wirelessly;
A casing in which the detection unit, the power transmission unit, the power reception unit, the transmission unit, and the reception unit are accommodated;
The casing is
A first accommodating part in which the detecting part, the power receiving part and the transmitting part are accommodated;
A second accommodating part in which the power transmission part and the receiving part are accommodated;
A fluid detector, comprising: a partition wall provided between the first housing portion and the second housing portion and separating the first housing portion and the second housing portion. The transmitter has a transmission coil capable of magnetically transmitting the signal,
The reception unit is disposed to face the transmission coil across the partition wall, and has a reception coil capable of magnetically receiving the signal transmitted from the transmission coil,
The power transmission unit has a primary coil that generates a magnetic field according to a supplied current,
The power receiving unit is disposed to face the primary coil across the partition, and has a secondary coil that generates electromagnetic induction according to a magnetic field generated by the primary coil,
The fluid detector according to claim 1, wherein a predetermined voltage is applied to the primary coil when detecting the state of the detection target fluid. The casing is made of metal;
The fluid detector according to claim 2, wherein the transmission coil, the reception coil, the primary coil, and the secondary coil are each wound around a core having a higher magnetic permeability than the casing. The casing is formed of resin,
The transmission coil and the reception coil are insert-molded in a state of being opposed to each other with a predetermined interval,
3. The fluid detector according to claim 2, wherein the primary coil and the secondary coil are insert-molded in a state in which the primary coil and the secondary coil are arranged to face each other at a predetermined interval. The detection unit has a pair of electrodes exposed to the detection target fluid,
5. The fluid detector according to claim 1, wherein the power received by the power receiving unit is supplied to the pair of electrodes. 6. A fluid detection device comprising the fluid detector according to claim 5,
A calculation unit that calculates a property value of the detection target fluid based on the signal received by the reception unit;
And a determination unit that determines a change in the property of the detection target fluid based on the property value of the detection target fluid calculated by the calculation unit.

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