JP2008008885A - Magnetic substance concentration measuring instrument and magnetic substance concentration measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic substance concentration measuring instrument and a magnetic substance concentration measuring method, which measure precisely a concentration of a magnetic substance and also measure continuously the very low concentration of the magnetic substance in a fluid. <P>SOLUTION: The magnetic substance concentration measuring instrument provided with: an excitation coil 11a; and an output coil 11b for generating an excitation voltage when an alternating current flows through the excitation coil 11a, has a measuring means 6 for measuring a change of a phase difference between a voltage of the excitation coil 11a and a voltage of the output coil 11b, and measures the concentration of the magnetic substance, based on the change of the phase difference generated when an inspection object is approached to the excitation coil 11a or/and the output coil 11b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a magnetic substance concentration measuring device and a magnetic substance concentration measuring method.

  For example, in a prime mover such as an engine having a reciprocating component such as a piston, the piston and the cylinder are worn by sliding between the piston and the cylinder, and a magnetic material such as iron powder is generated. Thus, when such a magnetic substance is generated, the magnetic substance flows along with the drain oil in the flow path through which the drain oil from the engine flows. Therefore, the magnetic substance contained in the drain oil of the flow path It is necessary to measure the concentration of the water as needed to accurately grasp the wear status of the equipment.

  In general, when grasping the wear state of equipment, the lubricating oil or drain oil is sampled manually and the concentration of the magnetic material is measured by a chemical method, or the flow path through which the lubricating oil or drain oil flows A magnetic substance concentration measuring device is arranged in the vicinity of to measure the concentration of the magnetic substance.

Here, as an example of a magnetic substance concentration measuring apparatus, a magnetized magnetic device including a magnetic field applying means and a magnetic measuring means including a magnetic sensor of a superconducting quantum interference element is provided in the vicinity of a flow path through which drain oil flows. Some detect only the magnetic field of the component (see, for example, Patent Document 1). As another example, an LC oscillation circuit for actual measurement in which the first coil is disposed near the drain oil flow path, and a correction coil in which the second coil is disposed at a position not affected by the magnetic substance of the drain oil. There is an LC generation circuit that detects the concentration of the magnetic substance by utilizing the difference between the oscillation frequency of the actual LC generation circuit and the oscillation frequency of the correction LC generation circuit (see, for example, Patent Document 2). .)
Japanese Patent Laid-Open No. 10-268013 JP 2005-83897 A

  However, there is a problem that the concentration of the magnetic substance cannot be measured with high accuracy by the chemical method, the magnetic component magnetic field, and the method of measuring the concentration of the magnetic substance simply by the difference in the oscillation frequency as in the conventional example. .

  Further, when the concentration of the magnetic material is measured by sampling a fluid such as lubricating oil or drain oil by manual work, there is a problem that it takes time and measurement can be performed only at a constant interval. Furthermore, in the case of using a conventional magnetic substance concentration measuring device, there is a problem that disturbance is generated due to accumulation of a solid content or a change in the flow rate of a fluid, and continuous and accurate measurement cannot be performed. Furthermore, even when using the magnetic substance concentration measuring apparatus of another example, it has been required to further reduce the noise and accurately measure the concentration of a small amount of magnetic substance.

  The present invention has been made in view of such circumstances, and measures a magnetic substance concentration with high accuracy, and further measures a magnetic substance concentration measuring apparatus and a magnetic substance for continuously measuring a minute concentration of a magnetic substance contained in a fluid. The object is to provide a concentration measurement method.

  The present invention is a magnetic concentration measuring apparatus comprising an excitation coil and an output coil that generates an excitation voltage when an alternating current flows through the excitation coil, wherein the voltage of the excitation coil and the output coil Measuring means for measuring a change in phase difference between the voltage and the magnetic material from the change in phase difference that occurs when the inspection object is brought close to the excitation coil and / or the output coil. The present invention relates to a magnetic substance concentration measuring apparatus characterized by grasping the concentration of the magnetic substance.

  In the present invention, it is preferable to use a lock-in amplifier for the measuring means.

  In the present invention, it is preferable to use the voltage of the exciting coil as a reference signal of the lock-in amplifier.

  In the present invention, as a means for bringing the inspection object close to the exciting coil and / or the output coil, the inspection object is introduced from the flow path through which the fluid containing the magnetic material flows or from the reservoir where the fluid containing the magnetic material accumulates. It is preferable to have driving means for

  The present invention is connected to a flow path through which a fluid containing a magnetic body flows or a reservoir in which a fluid containing a magnetic body accumulates, and a fluid supply / removal means and a detection means are arranged, and connected to the detection means. A signal processing unit for disposing a lock-in amplifier, wherein the detection unit introduces fluid by the fluid introduction / introduction means, and detects the magnetic substance at the time of fluid introduction from the output signal of the AC voltage through the detection unit. A correction detection signal at the time of fluid discharge, and the signal processing unit performs noise removal from each signal by a lock-in amplifier using a reference signal of the same frequency, and at the same time, Magnetic substance concentration characterized by detecting a phase difference, converting it to a DC voltage signal according to the amount of the detected phase difference, and detecting the difference between the converted values as the magnetic substance concentration Measuring device It takes things.

  The present invention is connected to a flow path through which a fluid containing a magnetic body flows or a reservoir in which a fluid containing a magnetic body accumulates, and a fluid supply / removal means and a detection means are arranged, and connected to the detection means. A signal processing unit for disposing a lock-in amplifier, wherein the detection unit detects and detects a magnetic substance when the fluid is introduced and introduced through the detection unit, and is corrected when the fluid is discharged. The signal processing unit obtains a detection signal, the signal processing unit performs noise removal from each signal by a lock-in amplifier using a reference signal having the same frequency, and then converts the signal to a DC voltage signal. The present invention relates to a magnetic substance concentration measuring apparatus configured to detect a magnetic substance concentration.

  In the present invention, the signal processing unit is configured to shift the phase of the reference signal or the phase of the detection signal of the magnetic material so that the value obtained by converting the output signal into a DC voltage signal approaches zero when the magnetic material is not detected. It is preferable.

  In the present invention, the detection means includes an output coil for obtaining a detection signal of the magnetic material, and an excitation coil, and an AC voltage is applied to the excitation coil to output an AC voltage output signal to the output coil. It is preferable to generate the magnetic body detection signal or the correction detection signal from the output signal, and to acquire the reference signal from the oscillation circuit connected to the excitation coil.

  In the present invention, the detection means is arranged by winding a plurality of excitation coils in opposite directions and arranging the detection coil between the plurality of excitation coils, so that the output signal of the detection coil becomes small. It is preferable to be configured as described above.

  In the present invention, it is preferable that the fluid lead-in / out means is configured to lead in / out the fluid by reciprocation of a piston.

  In the present invention, from a test object containing a magnetic material or a fluid containing a magnetic material, at least one of the concentration of the magnetic material, the rate of change of concentration, the amplitude of concentration change, the period of concentration change, and the concentration deviation at the time of multipoint measurement. It is preferable that one or more pieces of information be acquired and configured so that the state of the sliding object is determined from the correlation between the magnetic substance concentration obtained in advance and the state of the sliding object.

  In this invention, it is preferable to comprise so that the warning means which issues a warning or / and a warning according to the state of a sliding object may be provided.

  In the present invention, the configuration is such that the supply amount, supply timing, supply pressure, supply temperature, lubrication fluid injection method, and lubrication fluid properties of the lubricant are controlled according to the state of the slide. It is preferred that

  The present invention is a magnetic substance concentration measurement method using an excitation coil and an output coil that generates an excitation voltage when an alternating current flows through the excitation coil, the inspection object and the excitation coil or / And measuring the change in phase difference between the voltage of the exciting coil and the voltage of the output coil when the output coil is brought close to the magnet for grasping the concentration of the magnetic material. This relates to a method for measuring body concentration.

  In the present invention, it is preferable that the voltage signal of the output coil is partially inverted in phase and converted into a direct current to measure a change in phase difference.

  In the present invention, it is preferable to partially invert the phase of the voltage signal of the output coil using the voltage signal of the excitation coil.

  In the present invention, it is preferable that the inspection object is introduced from a flow path in which a fluid containing a magnetic body flows or a reservoir portion in which a fluid containing a magnetic body is accumulated to approach the excitation coil and / or the output coil.

The present invention introduces a fluid from a flow path through which a fluid containing a magnetic body flows or a reservoir in which a fluid containing a magnetic body accumulates to the detection unit, acquires a detection signal of the magnetic body from the fluid of the detection unit, and has the same frequency. The reference signal of the magnetic material is prepared, the noise detection signal is combined with the reference signal of the same frequency as the magnetic material, and noise is removed by a lock-in amplifier, which is processed to be converted into a DC voltage signal as an output value for the concentration of the magnetic material Treatment process at the time of fluid introduction,
The fluid is discharged from the detection unit, the detection signal for correction in the detection unit is acquired, and a reference signal having the same frequency is prepared, and noise is removed by a lock-in amplifier by combining the detection signal for correction and the reference signal of the same frequency. And a processing step at the time of fluid discharge processed so as to be converted into a DC voltage signal as an output value for comparison,
The present invention relates to a magnetic substance concentration measuring method, wherein the output value for concentration of the magnetic substance is corrected by the output value for comparison.

  In the present invention, in the processing step at the time of fluid introduction and the processing step at the time of fluid discharge, the detection signal for magnetic substance and the detection signal for correction are obtained from the output signal of AC voltage, and the detection signal for magnetic substance and the detection signal for correction are obtained. Together with a reference signal of the same frequency, the noise is removed from each signal by a lock-in amplifier, and at the same time, the phase difference between each signal and the reference signal and the effective value of the signal are detected, and the detected phase difference is detected. It is preferable to convert the output value for the concentration of the magnetic substance and the output value for comparison according to the amount of the magnetic material.

  In the present invention, the difference between the output value for the concentration of the magnetic substance and the output value for comparison is further reduced by direct current by alternately repeating the treatment process at the time of fluid introduction and the treatment process at the time of fluid discharge. It is preferable to convert it into a voltage signal, convert the difference into the concentration of the magnetic material based on the correlation obtained in advance, and eliminate measurement errors due to disturbances and changes over time.

  In the present invention, shifting the phase of the reference signal or the detection signal of the magnetic material to bring the value obtained by converting the output signal of the signal processing device into a DC voltage signal close to zero is maximized by the subsequent amplifier. Preferred above.

  In the present invention, from a test object containing a magnetic material or a fluid containing a magnetic material, at least one of the concentration of the magnetic material, the rate of change of concentration, the amplitude of concentration change, the period of concentration change, and the concentration deviation at the time of multipoint measurement. Obtaining one or more pieces of information and judging the state of the sliding object from the correlation between the magnetic substance concentration obtained in advance and the state of the sliding object performs self-diagnosis of this device and measures it in an appropriate state. It is preferable to always confirm that

  In the present invention, it is preferable to always confirm that measurement is performed in an appropriate state by issuing a warning or / and warning according to the state of the sliding object.

  In the present invention, it is preferable to control the supply amount, supply timing, supply pressure, supply temperature, lubrication fluid injection method, and lubrication fluid properties of the lubricant to the slide according to the state of the slide.

  As described above, according to the present invention, the voltage of the exciting coil, the voltage of the output coil, and the change in the phase difference between the signals generated according to the concentration of the magnetic material are utilized. By making the exciting coil and / or the output coil close to each other, this change in voltage and phase difference can be detected with high sensitivity. That is, the concentration of the magnetic material can be measured with high accuracy. In addition, since the present invention uses the phase difference generated between the excitation coil voltage and the output coil voltage and the output coil voltage change, the reactance change of the excitation coil due to the presence or absence of the magnetic substance, the magnetic substance Changes in the reactance of the output coil due to the presence or absence of the coil, changes in the eddy current generated in the inspection object, changes in the Joule loss due to the eddy current, changes in the eddy current generated in the surrounding objects of the coil, changes in the Joule loss due to the eddy current, etc. It is possible to measure the concentration of the magnetic substance with high accuracy by comprehensively capturing various changes in the magnetic field.

  According to the present invention, a reference signal having the same frequency as the excitation voltage is prepared, the detection signal of the magnetic material is obtained from the fluid in the detection unit, the phase difference from the reference signal and the voltage change of the output coil are measured, It is converted into a DC voltage signal according to the measured amount of phase difference, and then the detection signal for correction in the detection unit is obtained from the detection unit from which the fluid is discharged, and the phase difference from the reference signal is measured and measured. The phase difference is converted into a DC voltage signal according to the amount of the phase difference, and the difference between the value at the time of fluid introduction after the conversion and the value at the time of fluid discharge after the conversion is used as the concentration of the magnetic substance. The concentration of the magnetic material can be measured with extremely high accuracy by using the voltage change of the output coil. Note that the change in phase difference and the voltage change in the output coil are finally converted into effective values of voltage, which are used as magnetic substance detection signals.

  According to the present invention, a reference signal having the same frequency as the excitation voltage is prepared, the noise of the magnetic substance detection signal acquired from the fluid in the detection unit is removed by the band-pass filter, and the noise is combined with the reference signal. This is removed and converted to a DC voltage component for the concentration of the magnetic substance. Next, the correction detection signal obtained from the detection unit from which the fluid has been discharged is noise-removed together with the reference signal, and a direct current for comparison is removed. Converts to voltage component, and the difference between each DC component value after conversion is used as the concentration of the magnetic substance of the fluid, so that noise superimposed on the output signal at the time of measurement is removed, and the solid content accumulated by introducing and removing the fluid The minute concentration of the fluid magnetic substance can be accurately measured.

  Repeated fluid derivation and acquisition of multiple differences in each measured value, so multiple measurement data are processed to constantly eliminate measurement errors due to changes over time and continuously measure minute concentrations of fluid magnetic materials can do.

  In the present invention, the detection signal of the magnetic body at the time of fluid introduction and the detection signal for correction at the time of fluid discharge are acquired from the output signal of the AC voltage, and the phase difference between each signal and the reference signal is detected and detected. By converting to a DC voltage signal according to the amount of phase difference, a slight phase difference can be obtained as a large output value, and the magnetic substance concentration can be detected with high sensitivity, so the minute concentration of the magnetic substance in the fluid is suitably It can measure with high accuracy.

  As described above, according to the present invention, since the phase difference is used, it is possible to achieve various excellent effects that the concentration of the magnetic material can be continuously measured with high accuracy.

  A magnetic substance concentration measuring apparatus and a magnetic substance concentration measuring method, which are first examples of embodiments of the present invention, will be described. 1 to 8 show a first example of an embodiment of the present invention.

  The magnetic substance concentration measuring apparatus and the magnetic substance concentration measuring method of the first example include a fluid lead-in / out means (driving means) 2 and a detecting means 3 in a flow path 1 of a pipe through which a fluid such as drain oil containing magnetic powder flows. A detection unit 4 provided, a detection unit 3 of the detection unit 4 is connected to a signal processing unit (measurement unit) 6 provided with a signal processing device 5, and a measurement value display and abnormality determination are further connected to the signal processing unit 6. Device 7 is connected.

  The pipe flow path 1 extends in a straight line in the horizontal direction, and allows the lubricating oil to flow into and out of a device (not shown) provided with a sliding object. Here, the flow path 1 of the pipe is not limited to a straight line extending in the horizontal direction, but is a flow path extending in a curved line, a flow path extending with an angle, and a vertical direction. Or a channel extending in an oblique direction. The fluid is not limited to lubricating oil, and any fluid may be used. Furthermore, the sliding object is not limited to the driving piston and the driving cylinder, and any sliding object may be used.

  The detection unit 4 includes a cylindrical detection unit main body 9 that forms an opening 8 in the flow path 1, and a fluid introduction / extraction means 2 that slides inside the detection unit main body 9 to introduce and introduce lubricating oil (detection fluid). A piston 2 a, a rotating part 10 of a driving means for moving the piston 2 a of the fluid lead-in / out means 2 forward and backward, and a coil 11 of the detecting means 3 disposed on the outer peripheral part of the detecting part main body 9 are provided.

  In addition, the coil 11 of the detection means 3 is a detection coil disposed in proximity between two exciting coils 11a and 11a wound in opposite directions and connected in series. When an AC voltage is applied to the excitation coil 11a, an output signal of an AC voltage (excitation voltage) is generated in the detection coil 11b. Further, the two exciting coils 11a and 11a and the detecting coil 11b are adjusted so that the mutual inductance is substantially equal by adjusting the number of turns of the coil 11 and the distance between the coils 11 so that the mutual inductance is substantially equal. It is adjusted so that The number of exciting coils 11a and detecting coils 11b is not particularly limited. Furthermore, it is preferable to provide a shield such as an aluminum tube outside the coil 11 so that noise does not enter from the outside.

  Further, as shown in FIG. 2, the coil 11 of the detection means 3 includes one excitation coil 11c and a detection coil (output coil) 11d arranged in the vicinity of the one excitation coil 11c. Similarly, in this case, when an AC voltage is applied to the excitation coil 11c, an output signal of an AC voltage (excitation voltage) is generated in the detection coil 11d, and the magnetic substance is not detected. Sometimes, the output signal of the AC voltage (excitation voltage) of the detection coil 11d is adjusted to be small.

  As shown in FIG. 3, the signal processing unit 6 is connected to the detection coil 11 b and amplifies a weak waveform signal so as to obtain a magnetic detection signal or a correction detection signal from the output signal of the detection coil 11 b. An amplifying circuit 12, a band pass filter 13 connected to the amplifying circuit 12 for removing noise of the waveform signal within a predetermined range, a sine wave oscillating circuit 14 for obtaining a sine wave for excitation, and a sine wave oscillating circuit 14. A phase circuit 15 for shifting the phase of the sine wave, and an edge trigger circuit 16 connected to the phase circuit 15 to convert the sine wave into a rectangular wave.

  Here, the phase circuit 15 may shift the phase by 10 ° to 170 °, preferably 45 ° to 135 °, and more preferably about 90 ° in the state of non-detection of the magnetic material at the time of setting or adjustment. preferable. Note that it may be shifted somewhat before and after due to the electrical shift of the waveform. Further, the phase circuit 15 may be located between the bandpass filter 13 and the signal processing device 5, and the detection signal of the magnetic material and the detection signal for correction may be shifted instead of the reference signal. Further, the signal processing device 5 is preferably a lock-in amplifier, but may be any device as long as it can measure a change in phase difference.

  The signal processing unit 6 includes a signal processing device 5 connected to the band-pass filter 13 and the edge trigger circuit 16, and a low-pass filter 17 connected to the signal processing device 5 for converting an output signal into a DC voltage signal. An amplifier 18 connected to the low-pass filter 17 for amplifying a DC voltage signal, an AC signal transmission circuit 19 connected to the amplifier 18 and transmitting only the fluctuation amount of the DC voltage signal due to the introduction and detection of the detection fluid, and AC signal transmission And an amplifier 20 connected to the circuit 19. Here, between the AC signal transmission circuit 19 and the amplifier 20, as shown in FIG. 4, a DC conversion circuit 21 that converts an AC signal corresponding to the movement of the piston 2 a into a DC signal is provided to facilitate subsequent processing. You may make it do.

  Further, the measurement value display and abnormality determination device 7 is connected to the amplifier 20 of the signal processing unit 6 as shown in FIGS. 1 to 4 and converts the signal into the concentration of the magnetic substance. A control unit 22 that performs predetermined control is provided so that lubrication control, warning of abnormality, and the like can be performed with respect to the lubrication state of the sliding object.

  Hereinafter, the operation of the first example of the embodiment of the present invention will be described.

  When measuring the concentration of the magnetic powder contained in the lubricating oil (fluid), the lubricating oil is introduced into the detection unit 4 from the flow path 1 by pulling the piston 2a of the fluid lead-in / out means 2, and the lubricating oil The output signal is measured and processed in a certain state. Here, it is preferable that the piston 2a of the fluid lead-in / out means 2 draws in the lubricating oil until the drain oil is located at about one half of the exciting coil 11a and about half of the detecting coil 11b.

  When the measurement process is performed with the drain oil introduced into the detection unit 4 (processing step at the time of introducing the fluid), the lubricant oil from the detection unit 4 is passed through the detection coil 11b, the amplification circuit 12, and the band-pass filter 13. Thus, the detection signal of the magnetic material is acquired ((A ′) in FIG. 6), and the excitation coil 11a, the sine wave oscillation circuit 14, the phase circuit 15 and the edge trigger circuit 16 are used to excite the phase at a predetermined angle. A rectangular-wave reference signal that generates a constant phase difference at the same frequency as the voltage is prepared ((B ′) in FIG. 6), and the signal processing device 5 performs noise removal together with the reference signal, and also detects the magnetic material. The phase difference between the signal and the reference signal is detected and converted to a smooth DC voltage signal as an output value for the concentration of the magnetic substance by the low-pass filter 17 ((D ′) in FIG. 6), and the amplifier 1 Input to the AC signal transmission circuit 19 via the. In FIG. 6B ′, the phase is set so as to be shifted by about 90 °. FIG. 6C ′ shows a state in which the detection signal of the magnetic material is inverted by the reference signal, and this area. Is integrated (D ′) in FIG.

  Subsequently, the piston 2a of the fluid lead-in / out means 2 is pushed out to discharge (lead out) the lubricating oil in the detection unit 4, and the output signal in a state where there is no lubricating oil (the fluid lead-in / out means 2 itself) is measured. Here, the time interval of the reciprocating motion of the fluid lead-in / out means 2 varies depending on the viscosity of the fluid to be measured, but is preferably performed at intervals of several seconds.

  When the measurement process is performed in a state in which the lubricating oil is discharged (derived) from the detection unit 4 (processing step at the time of fluid discharge), the detection unit 4 passes through the detection coil 11b, the amplification circuit 12, and the bandpass filter 13. A correction detection signal is acquired ((A) in FIG. 5), and the excitation coil 11a, the sine wave oscillation circuit 14, the phase circuit 15 and the edge trigger circuit 16 are shifted in phase by a predetermined angle to be the same as the excitation voltage. A rectangular wave reference signal that generates a constant phase difference at a frequency is prepared ((B) in FIG. 5), and the signal processing device 5 performs noise removal together with the reference signal, and also detects the correction detection signal and the reference signal. Is converted into a smooth DC voltage signal as an output value for comparison by the low-pass filter 17 ((D) in FIG. 5), and the AC signal is passed through the amplifier 18. Input to the over circuit 19. In FIG. 5B, the phase is set so as to be shifted by about 90 °. FIG. 5C shows a state in which the detection signal of the magnetic material is inverted by the reference signal, and this area is integrated. When processed, it becomes (D) of FIG.

  Then, the AC signal transmission circuit 19 calculates a difference ΔV from the magnetic substance concentration output value and the comparison output value as shown in FIG. 6 so as to correct the magnetic substance concentration output value, The measured value display and abnormality determination device 7 converts the difference into the concentration of the magnetic substance by the correlation (function processing) with the concentration obtained in advance. Here, the output value (DC voltage signal) for concentration of the magnetic substance and the output value for comparison (DC voltage signal) are obtained by the signal processing device 5 from the phase difference Δf between the output signal of the magnetic substance and the reference signal. , And a correction output signal, a reference signal, and a phase difference (not shown) may be detected and converted according to the detected amount of phase difference.

  Subsequently, by continuously reciprocating the piston 2 a of the fluid lead-in / out means 2, measurement processing (processing step at the time of fluid introduction) in a state where the lubricant is introduced into the detection unit 4, The measurement process in the state where the lubricating oil is discharged (derived) from the fluid (processing process at the time of fluid discharge) is repeated alternately and compared with the output value for the concentration of the magnetic substance by the AC signal transmission circuit 19 or the like. A difference signal is detected from the output value for use and a moving average process is performed, and an average value of the concentration of the magnetic substance is obtained via the measured value display and abnormality determination device 7. The output value for the concentration of the magnetic substance is an AC signal that moves up and down with respect to the output value for comparison by the reciprocating motion of the fluid lead-in / out means 2 as shown in FIG. Further, this AC signal may be converted into a DC signal by using the DC conversion circuit 21.

  Further, in the measurement display and abnormality determination device 7, as shown in FIG. 7, the correlation (reference data) between the sliding state of the sliding object in the piston of the prime mover and the concentration of the magnetic material is input in advance by the control unit 22. (Step S1), the concentration of the magnetic substance, the change rate of the concentration of the magnetic substance, the amplitude of the change in the concentration of the magnetic substance, the magnetic property from the fluid containing the magnetic substance (test object) via the signal processing unit 6 and the like At least one piece of information is acquired from the period of concentration change of the body and the concentration deviation at the time of multipoint measurement (step S2), and then from the correlation (reference data) and the fluid containing the magnetic substance (test object) The obtained information is compared (step S3), the sliding state of the sliding object such as the piston is determined (step S4), and the drain oil (lubricating fluid) for the sliding object is determined according to the sliding state of the sliding object such as the piston. Supply amount, supply Control of the period, supply pressure, supply temperature, drain oil (lubricating fluid) injection method, drain oil (lubricating fluid) properties (step S5), and the concentration of magnetic powder exceeds a certain concentration If it is determined that the amount of wear of the sliding object is large, it is notified that the maintenance time has been reached, from the measured value display / abnormality determination device 7 to the administrator via a warning display, warning, warning light (step) S6).

  As described above, according to the first example of the embodiment, the phase difference generated between the voltage of the excitation coil 11a and the voltage of the detection coil (output coil) 11b is used, and an inspection object including a magnetic material is used. When the object is brought close to the excitation coil 11a or / and the output coil 11b, the change in phase difference that occurs according to the concentration of the magnetic material is used, so that the concentration of the magnetic material can be accurately measured. it can. The first example of the embodiment uses the phase difference generated between the voltage of the excitation coil 11a and the voltage of the detection coil 11b and the voltage change of the output coil 11b. Changes in the reactance of the coil 11a, changes in the reactance of the detection coil (output coil) 11b depending on the presence or absence of a magnetic material, changes in eddy current generated in the inspection object, changes in Joule loss due to eddy current, Various changes such as changes in eddy currents generated and changes in Joule loss due to eddy currents can be comprehensively captured, and the concentration of the magnetic material can be accurately measured. Here, when measuring the concentration of the magnetic material, the change in reactance of the excitation coil 11a due to the presence or absence of the magnetic material, the change in reactance of the detection coil (output coil) 11b due to the presence or absence of the magnetic material, Measured using the phase difference of some of the changes in eddy currents generated, changes in Joule loss due to eddy currents, changes in eddy currents generated in surrounding objects of the coil, changes in Joule loss due to eddy currents, etc. In this case, unlike the case of the voltage phase difference, it is affected by other changes, and therefore the concentration of the magnetic substance cannot be measured with high accuracy.

  In fact, according to the results of experiments conducted by the present inventor, as shown in the graph of FIG. 8, when a fluid (inspection object) containing several hundred ppm of iron powder is measured in the embodiment, the inspection object The output (concentration) increases simultaneously with the input of the test substance, and the output (concentration) decreases as the test object is discharged. The response to the magnetic substance is clear and rapid, and the concentration of the magnetic substance can be accurately measured. Is clear.

  In the first example, when the lock-in amplifier of the signal processing device 5 is used as the measuring means, the lock-in amplifier detects the phase difference between the detection signal of the magnetic material and the reference signal, removes noise, and detects the detected phase difference. Therefore, it is possible to detect the concentration of the magnetic body with high sensitivity with a slight phase difference and to measure the minute concentration of the magnetic body of the lubricating oil with good accuracy.

  Further, in the first example, when the voltage of the exciting coil 11a is used as a reference signal of the lock-in amplifier, a detection signal of the magnetic material when the lubricating oil is introduced from the output signal of the AC voltage, and a detection for correction when the lubricating oil is discharged Since the signal is acquired, the phase difference can be easily detected by the lock-in amplifier and noise can be removed, and the minute concentration of the magnetic material of the lubricating oil can be measured with good accuracy.

  In the first example, as a means for bringing the inspection object and the excitation coil 11a and / or the output coil 11b closer, an inspection is performed from a flow path through which a fluid containing a magnetic body flows or from a reservoir portion in which the fluid containing the magnetic body accumulates. When the driving means for introducing the object is provided, the inspection object of the fluid is easily acquired or discharged, so that the minute concentration of the magnetic substance of the lubricating oil can be continuously measured with high accuracy.

  According to the first example, the detection signal of the magnetic material is acquired from the fluid in the detection unit 4 and a reference signal having the same frequency is prepared, and the change in phase difference from the reference signal and the voltage change in the output coil 11b are measured. Then, the signal is converted into a signal corresponding to the amount of the measured phase difference, and then the correction detection signal in the detection unit 4 is acquired from the detection unit 4 from which the fluid has been discharged, and the change in the phase difference from the reference signal is changed. It is measured and converted into a signal corresponding to the measured amount of phase difference, and the difference between the converted value at the time of fluid introduction and the converted value at the time of fluid discharge is used as the magnetic substance concentration. The concentration of the magnetic material can be measured with extremely high accuracy by using the change and the voltage change of the output coil 11b. Note that the change in phase difference and the voltage change in the output coil 11b are finally converted into an effective voltage value and used as a magnetic substance detection signal.

  Further, the concentration of the magnetic material is acquired as a measured value of the change width in one time of the introduction / extraction of the lubricating oil, and the signal value is obtained continuously by continuously introducing / extracting the lubricating oil. By averaging the data, it is possible to continuously measure the minute concentration of the magnetic substance in the drain oil by constantly eliminating the effect of drift of the reference point (zero point) and offset change (fluctuation) due to changes over time. it can.

  In the first example, when the phase of the reference signal or the phase of the detection signal of the magnetic material is set to be shifted from the other signal, the amplification of the signal by the amplifiers 18 and 25 can be performed more easily. The minute concentration of the magnetic material can be measured suitably. Here, when the phase is shifted by 10 ° to 170 °, the minute concentration of the magnetic material can be measured, and when the phase is shifted by 45 ° to 135 °, the minute concentration of the magnetic material can be suitably measured. Is shifted about 90 °, the minute concentration of the magnetic material can be measured very suitably.

  In the first example, the phase of the reference signal or the detection signal of the magnetic material is shifted, and when the magnetic material is not detected, the value obtained by converting the output signal of the signal processing device (lock-in amplifier) 5 into a DC voltage signal is set to zero. When approaching, the signal can be easily amplified, so that the minute concentration of the magnetic substance of the drain oil can be suitably measured.

  In the first example, the detection means 3 includes a detection coil 11b that acquires a detection signal of a magnetic material, and an excitation coil 11a. An AC voltage is applied to the excitation coil 11a and an AC voltage is applied to the detection coil 11b. Is generated, and a magnetic detection signal or a correction detection signal is acquired from the output signal, and a reference signal is acquired from the oscillation circuit 14 or the like connected to the excitation coil 11a. Since the voltage and phase change according to the concentration of the magnetic material by the AC voltage, the concentration of the magnetic material can be easily measured, and the minute concentration of the magnetic material of the lubricating oil can be suitably measured. Further, since the exciting coil 11a is used, a reference signal having the same frequency as the output signal of the detecting coil 11b can be easily prepared.

  In the first example, the detection means 3 is arranged by winding a plurality of excitation coils 11a in opposite directions and arranging a detection coil 11b between the plurality of excitation coils 11a, and outputting the detection coil 11b. When the signal is configured to be small, the concentration of the magnetic substance is detected with high sensitivity via the amplifiers 18 and 25, so that the minute concentration of the magnetic substance of the drain oil can be accurately measured.

  In the first example, when the fluid lead-in / out means 2 is configured to lead in and out the drain oil by the reciprocating motion of the piston 2a, the accumulated solid content is easily discharged and continuously measured, Measurement errors due to changes over time can be eliminated, and the minute concentration of the magnetic substance of the drain oil can be continuously measured with high accuracy. In addition, deposits such as solids are suitably eliminated by the reciprocating motion of the piston 2a, so that periodic air blowing and mechanical removal can be eliminated. Furthermore, even when the drain oil is highly viscous, the drain oil can be reliably led out at regular intervals by the reciprocating motion of the piston 2a, so that the concentration of the magnetic substance of the drain oil can be continuously and accurately measured. it can.

  In the first example, the signal processing unit 6 includes a signal processing device 5 that performs noise removal from a detection signal of a magnetic body at the time of fluid introduction or a detection signal for correction at the time of fluid discharge using a reference signal having the same frequency. The noise of the magnetic body detection signal acquired from the lubricating oil in the detection unit 4 is removed by the band-pass filter 13, and the noise is removed by the signal processing device 5 together with the reference signal of the same frequency. The detection signal for correction acquired from the detection unit 4 from which the drain oil has been discharged is noise-removed by the signal processing device 5 together with the reference signal, and the difference between the values of the converted signals is determined by the magnetic material of the drain oil. Since the concentration is used, the noise superimposed on the output signal at the time of measurement can be removed, and the minute concentration of the magnetic substance of the drain oil can be measured with high accuracy.

  In the first example, from a fluid (inspection object) containing a magnetic material, at least one of the concentration of the magnetic material, the concentration change rate, the concentration change amplitude, the concentration change cycle, and the concentration deviation during multipoint measurement. If the sliding state of the sliding object is determined from the correlation between the magnetic substance concentration obtained in advance and the state of the sliding object, the state of the sliding object such as a piston is confirmed, maintenance, drain oil (lubricating fluid ) Can be controlled very easily and accurately.

  In the first example, if a measurement display and an abnormality determination device (warning means) 7 that issues a warning or / and an alarm according to the state of the sliding object are provided, the state confirmation and maintenance of the sliding object such as a piston can be performed very easily and quickly. It can be carried out.

  In the first example, the amount of drain oil (lubricating fluid) supplied to the sliding object, the supply timing, the supply pressure, the supply temperature, the drain oil (lubricating fluid) injection method, and the properties of the lubricating fluid are determined according to the state of the sliding object. When controlled, the sliding state of the sliding object such as the piston can be suitably maintained.

  A magnetic substance concentration measuring apparatus and a magnetic substance concentration measuring method as a second example of the embodiment of the present invention will be described. 9 to 11 show a second example of the embodiment of the present invention.

  The magnetic substance concentration measuring device and the magnetic substance concentration measuring method of the second example include a fluid extraction / introduction means 32 and a detection means 33 in a flow path 31 of a pipe through which a fluid such as drain oil containing magnetic powder flows down. 34, a signal processing unit 36 including a lock-in amplifier 35 and the like is connected to the detection means 33 of the detection unit 34, and a measurement value display and abnormality determination device 37 is further connected to the signal processing unit 36. Yes.

  Here, the flow path 31 of the piping discharges drain oil from a device (not shown) such as a diesel engine provided with a drive piston, a drive cylinder, and the like. There is provided an on-off valve 39 as a closing means for forming an oil reservoir 38 and a branch passage 40 arranged so as to avoid the on-off valve 39. The branch passage 40 is located upstream of the reservoir 38. A branch port 41 formed and a junction port 42 formed on the downstream side of the on-off valve 39 are provided, and drain oil overflowing from the reservoir 38 is caused to flow downstream. Further, the fluid is not limited to drain oil, and any fluid may be used as long as it includes a magnetic material.

  The detection unit 34 includes a cylindrical detection unit main body 44 that forms an opening 43 in the reservoir unit 38 so as to be disposed in the flow path 31 between the on-off valve 39 and the branch port 41, and a slide inside the detection unit main body 44. A plurality of coils of the detecting means 33 disposed on the outer peripheral portion of the detecting portion main body 44; a piston 32a of the fluid leading-in / out means 32 that moves; a rotating portion 45 of a driving means that causes the piston 32a of the fluid leading-in / out means 32 to move forward and backward; 46 is provided.

  The plurality of coils 46 of the detection means 33 are two detection coils 46a and 46a that are wound in opposite directions and connected in series, and two detection coils 46a and 46a for detection. When an AC voltage is applied to the excitation coil 46a, an AC voltage output signal is generated in the detection coil 46b and the output signal of the detection coil 46b is small when no magnetic material is detected. It has been adjusted to be. In addition, the number of turns of the coil 46 and the distance between the coils 46 are adjusted so that the mutual inductances of the two exciting coils 46a and 46a and the detection coil 46b are substantially equal, and the mutual inductances are substantially uniform. It is adjusted to become. Here, it is preferable to adjust the output signal of the detection coil 46b to be small. Further, the number of exciting coils 46a and detecting coils 46b is not particularly limited. Furthermore, it is preferable to provide a shield such as an aluminum tube outside the coil 46 so that noise does not enter from the outside. Similarly to the first example, the coil 46 may include one excitation coil and a detection coil (output coil) disposed in proximity to one excitation coil.

  The signal processing unit 36 is connected to the detection coil 46b and amplifies a weak waveform signal so as to obtain a magnetic detection signal or a correction detection signal from the output signal of the detection coil 46b. A band-pass filter 48 that is connected to the circuit 47 and eliminates noise of the waveform signal within a predetermined range, a sine wave oscillation circuit 49 that is connected to the excitation coils 46a and 46a to obtain an excitation sine wave, and a sine wave oscillation circuit 49, and a phase circuit 50 that shifts the phase of the sine wave, and an edge trigger circuit 51 that is connected to the phase circuit 50 and converts the exciting sine wave into a rectangular wave. Here, the phase circuit 50 may be positioned between the bandpass filter 48 and the lock-in amplifier 35, and the magnetic detection signal and the correction detection signal may be shifted by about 90 ° instead of the reference signal. The phase circuit 50 preferably shifts the phase by 90 ° when the magnetic material is not detected. However, the phase circuit 50 may shift the phase slightly back and forth due to an electrical shift of the waveform. Further, the phase circuit 50 may set the phase shift in a range of 10 ° to 170 ° in a state where no magnetic substance is detected, as in the first example.

  The signal processing unit 36 includes a lock-in amplifier 35 that is connected to the band-pass filter 48 and the edge trigger circuit 51, and a low-pass filter 52 that is connected to the lock-in amplifier 35 and converts the output signal into a DC voltage signal. , An amplifier 53 connected to the low-pass filter 52 for amplifying a DC voltage signal, an AC signal transmission circuit 54 connected to the amplifier 53, and an amplifier 55 connected to the AC signal transmission circuit 54. Here, between the AC signal transmission circuit 54 and the amplifier 55, as shown in FIG. 11, a DC conversion circuit 56 for converting an AC signal corresponding to the movement of the piston 32a into a DC signal is provided, and the subsequent processing is facilitated. You may make it do.

  Further, the measured value display / abnormality determination device 37 is connected to the amplifier 55 of the signal processing unit 36 so as to convert the signal into the concentration of the magnetic substance and to give an abnormality warning. Further, the measurement value display and abnormality determination device 37, like the first example, performs a predetermined control so as to perform lubrication control, warning of abnormality, etc. with respect to the lubrication state of a sliding object such as a piston ( (Not shown) may be provided.

  Hereinafter, the operation of the second example of the embodiment of the present invention will be described.

  When measuring the concentration of the magnetic substance powder contained in the drain oil (fluid), the on-off valve 39 of the flow path 31 is closed in a state where the piston 32a of the fluid lead-in / out means 32 of the detection unit 34 is pushed in advance, and the reservoir unit A certain amount of drain oil is stored in 38. Next, by pulling in the piston 32a of the fluid lead-in / out means 32, the drain oil in the reservoir 38 is introduced into the detector 34, and the output signal is measured in a state where there is drain oil. Here, it is preferable that the piston 32a of the fluid lead-in / out means 32 draws in the drain oil until the drain oil is located at about one half of the excitation coil 46a and about half of the detection coil 46b.

  When performing measurement processing with the drain oil introduced into the detection unit 34 (processing step when introducing fluid), the drain oil from the detection unit 34 is passed through the detection coil 46b, the amplification circuit 47, and the band-pass filter 48. A magnetic substance detection signal is acquired ((A ′ in FIG. 6)), and the magnetic substance detection signal (excitation voltage) is passed through the excitation coil 46a, the sine wave oscillation circuit 49, the phase circuit 50, and the edge trigger circuit 51. ) And a rectangular wave reference signal set at the same frequency and shifted by about 90 ° ((B ′) in FIG. 6), and by the lock-in amplifier 35, the output signal of the magnetic material and the reference signal of the same frequency And is converted into a smooth DC voltage signal as an output value for the concentration of the magnetic substance by the low-pass filter 52 ((D ′) in FIG. 6), and AC is passed through the amplifier. Input to No. transmission circuit 54. Note that (C ′) in FIG. 6 shows a state in which the detection signal of the magnetic material is inverted by the reference signal, and when this area is integrated, (D ′) in FIG. 6 is obtained.

  Subsequently, the drain oil in the detection unit 34 is discharged (derived) by pushing out the piston 32a of the fluid introducing / introducing means 32, and the output signal in a state where there is no drain oil (fluid introducing / introducing means 32 itself) is measured. Here, although the time interval of the reciprocating motion of the fluid lead-in / out means 32 varies depending on the viscosity of the fluid to be measured, it is preferably performed at intervals of several seconds.

  When the measurement process is performed in a state in which the drain oil is discharged (derived) from the detection unit 34 (processing step at the time of fluid discharge), the detection coil 46b, the amplification circuit 47, and the bandpass filter 48 are extracted from the drain oil of the detection unit 34. (A in FIG. 5) and a correction detection signal (excitation voltage) via the excitation coil 46a, the sine wave oscillation circuit 49, the phase circuit 50, and the edge trigger circuit 51. ) And a rectangular-wave reference signal set at the same frequency and shifted by about 90 ° (FIG. 5B), the lock-in amplifier 35 combines the correction detection signal and the reference signal of the same frequency. The low-pass filter 52 converts the noise into a smooth DC voltage signal as a comparison output value ((D) in FIG. 5), and transmits the AC signal through an amplifier. The input to the circuit 54. FIG. 5C shows a state in which the detection signal of the magnetic material is inverted by the reference signal, and when this area is integrated, FIG. 5D is obtained.

  Then, a difference ΔV is obtained from the output value for the concentration of the magnetic substance and the output value for comparison so as to correct the output value for the concentration of the magnetic substance by the AC signal transmission circuit 54 as shown in FIG. It converts into a DC voltage signal, and the measured value display and abnormality determination device 37 converts the difference into the concentration of the magnetic material by the correlation (function processing) obtained in advance. Here, the output value for the concentration of the magnetic substance (DC voltage signal) and the output value for comparison (DC voltage signal) are obtained by the lock-in amplifier 35 from the phase difference Δf between the output signal of the magnetic substance and the reference signal. , And a correction output signal, a reference signal, and a phase difference (not shown) may be detected and converted according to the detected amount of phase difference.

  Subsequently, by continuously reciprocating the piston 32a of the fluid lead-in / out means, a measurement process in a state in which the drain oil is introduced into the detection unit 34 (a processing step at the time of introducing the fluid), and from the detection unit 34 The measurement process (process at the time of fluid discharge) with the drain oil discharged (derived) is alternately and continuously repeated, and the output value for the concentration of the magnetic material is compared with the AC signal transmission circuit 54 and the like. A difference signal is detected from the output value and a moving average process is performed, and an average value of the concentration of the magnetic substance is obtained via the measured value display and abnormality determination device 37. Note that the output value for the concentration of the magnetic substance is an AC signal that moves up and down with respect to the output value for comparison by the reciprocating motion of the fluid lead-in / out means, as shown in FIG. 6 (D ′). Further, this AC signal may be converted into a DC signal by using the DC conversion circuit 56.

  If the concentration of the magnetic powder exceeds a certain level in the state where the drain oil is measured, the amount of wear of the equipment including the drive fluid inlet / outlet means and the drive cylinder is large, and maintenance is required. It is notified that the time has arrived, the measured value display and abnormality determination device 37 notifies the administrator via a warning display, a warning sound, and a warning light. When a control unit (not shown) is provided, as in the first example, the correlation (reference data) between the sliding state of the sliding object such as the piston and the concentration of the magnetic body, and the magnetic body Compared with the information obtained from the fluid (inspection object) that is included, the sliding state of the sliding object such as a piston is judged, drain oil (lubricating fluid) is controlled for the sliding object, and an alarm is issued. good.

  As described above, according to the second example of the embodiment, the magnetic body detection signal obtained from the drain oil in the detection unit 34 is noise-removed by the lock-in amplifier 35 together with the reference signal of the same frequency, and the magnetic The signal is converted into a DC voltage component for body concentration, and then the correction detection signal acquired from the detection unit 34 from which the drain oil has been discharged is removed by the lock-in amplifier 35 together with the reference signal of the same frequency. Because it converts to a DC voltage component for comparison, and the difference between the DC component values after conversion is the concentration of the magnetic substance of the drain oil, noise superimposed on the output signal at the time of measurement is removed and fluid derivation is performed. The drain oil can be led in and out by means, the accumulated solid content can be discharged, and the minute concentration of the magnetic substance of the drain oil can be measured with high accuracy. In addition, the second example of the embodiment uses a phase difference generated between the voltage of the excitation coil 46a and the voltage of the detection coil 46b, as in the first example. Change in reactance of 46a, change in reactance of detection coil (output coil) 46b depending on the presence or absence of magnetic material, change in eddy current generated in test object, change in Joule loss due to eddy current, generated in surrounding objects of coil It is possible to comprehensively capture various changes such as changes in eddy currents and joule loss due to eddy currents, and accurately measure the concentration of the magnetic material. Here, when measuring the concentration of the magnetic material, the change in the reactance of the excitation coil 46a due to the presence or absence of the magnetic material, the change in the reactance of the detection coil (output coil) 46b due to the presence or absence of the magnetic material, Measured using the phase difference of some of the changes in eddy currents generated, changes in Joule loss due to eddy currents, changes in eddy currents generated in surrounding objects of the coil, changes in Joule loss due to eddy currents, etc. In this case, unlike the case of the voltage phase difference, it is affected by other changes, so that the concentration of the magnetic substance cannot be measured with high accuracy.

  In addition, the concentration of the magnetic material is acquired as each DC component in one drain oil introduction / removal operation, and the drain oil is repeatedly introduced / removed to obtain a plurality of differences in the value of each DC component. Can be continuously measured to eliminate the influence of drift of reference point (zero point) and offset change (fluctuation) due to changes over time, and continuously measure the minute concentration of magnetic substance in drain oil. .

  In the second example, the detection signal of the magnetic body when drain oil is introduced and the detection signal for correction when drain oil is discharged are obtained from the output signal of the AC voltage, and the phase difference between each signal and the reference signal is obtained by the lock-in amplifier 35. Is detected and converted into a signal corresponding to the detected amount of phase difference, the magnetic substance concentration is detected with high sensitivity with a slight phase difference, so the minute concentration of the magnetic substance in the drain oil is measured accurately and suitably. can do.

  In the second example, when the phase of the reference signal or the detection signal of the magnetic material is shifted, and the value obtained by converting the output signal of the lock-in amplifier 35 to a DC voltage signal is close to zero when the magnetic material is not detected, Since the amplification can be easily performed, the minute concentration of the magnetic substance of the drain oil can be suitably measured.

  In the second example, if the phase of the reference signal or the phase of the detection signal of the magnetic material is shifted by about 90 ° from the other signal, the signal amplification by the amplifiers 53 and 55 can be performed more easily. Can be measured very suitably.

  In the second example, the detection means includes a detection coil 46b for obtaining a detection signal of the magnetic material, and an excitation coil 46a. An AC voltage is applied to the excitation coil 46a, and an AC voltage is applied to the detection coil 46b. When an output signal is generated, a magnetic substance detection signal or a correction detection signal is acquired from the output signal, and a reference signal is acquired from the oscillation circuit 49 or the like connected to the excitation coil 46a. Since the voltage and the phase change according to the concentration of the magnetic body due to the voltage, the concentration of the magnetic body can be easily measured, and the minute concentration of the magnetic body of the drain oil can be preferably measured. Further, since the exciting coil 46a is used, a reference signal having the same frequency as the output signal of the detecting coil 46b can be easily prepared.

  In the second example, the detection means arranges the plurality of excitation coils 46a wound in opposite directions, arranges the detection coil 46b between the plurality of excitation coils 46a, and outputs an output signal of the detection coil 46b. Since the concentration of the magnetic substance is detected with high sensitivity via the amplifiers 53 and 55, the minute concentration of the magnetic substance of the drain oil can be accurately measured.

  In the second example, when the fluid lead-in / out means is configured to lead out / inject the drain oil by the reciprocating motion of the piston 32a, the accumulated solid content is easily discharged and continuously measured, so that the disturbance and time Measurement errors due to changes can be eliminated, and the minute concentration of the magnetic material of the drain oil can be continuously measured with high accuracy. Moreover, since deposits such as solids are suitably eliminated by the reciprocating motion of the piston 32a, periodic air blow and mechanical removal can be eliminated. Furthermore, even if the drain oil is highly viscous, the drain oil can be reliably led out at regular intervals by the reciprocating motion of the piston 32a, so that the concentration of the magnetic substance in the drain oil can be continuously measured with high accuracy. it can. Furthermore, the second example can obtain substantially the same operational effects as the first example.

  Hereinafter, a magnetic substance concentration measuring apparatus which is a third example of the embodiment of the present invention will be described. FIG. 12 shows a third example of the embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 9 denote the same components.

  The magnetic substance concentration measuring device of the third example is a modification of the flow path 31 of the pipe through which a fluid such as drain oil flows, and the flow path 61 of the third example has a detection unit 34 that is substantially the same as the first example. Connected.

  The flow path 61 of the pipe of the second example discharges drain oil from a device (not shown) such as a diesel engine provided with a drive piston and a drive cylinder. A main flow path 62 that is curved and extended in the vertical direction from the horizontal direction, an opening / closing valve 63 of the closing means disposed in a vertical portion of the main flow path 62, and the first example to avoid the opening / closing valve 63; A branch channel 66 arranged to form a branch port 64 and a junction port 65 in substantially the same manner, an extended channel 67 extending in a horizontal direction at a predetermined length from between the on-off valve 63 and the branch port 64, A small-diameter communication channel 68 that connects the end side of the extension channel 67 and the horizontal portion of the main channel 62 is provided.

  Here, the main flow path 62 from the branch port 64 to the opening / closing valve 63 of the closing means serves as a first reservoir 69 for accumulating old drain oil fluid, and the extended flow path 67 and the communication flow path 68 are newly provided. The second reservoir 70 receives and stores the drain oil fluid. Further, the branch flow channel 66 is configured to flow the drain oil overflowing from the first reservoir 69 to the downstream side as in the first example. Further, the connecting flow path 68 is arranged so that the drain oil flows in first than the vertical portion of the main flow path 62.

  On the other hand, the detection unit 34 includes a cylindrical detection unit main body 44 that forms an opening 43 in the second reservoir 70 so as to be disposed at a joining portion of the extension channel 67 and the communication channel 68, and a detection unit main body. The piston 32a of the fluid lead-in / out means 32 that slides inside the 44, the drive means (not shown) for driving the piston 32a of the fluid lead-in / out means 32, and the detection means disposed on the outer periphery of the detection unit main body 44 33, a plurality of coils 46, a signal processing unit 36 of the detection means 33 that controls the signal of the coil 46, and a measurement value display and abnormality determination device 37 connected to the signal processing unit 36. In addition, the detection unit main body 44 of the detection unit 34 is disposed so as to extend from the end of the extension flow path 67 in order to increase the reliability of fluid introduction / extraction.

  Hereinafter, the operation of the third example of the embodiment of the present invention will be described.

  When measuring the concentration of the magnetic powder contained in the drain oil, the on-off valve 63 of the main flow path 62 of the pipe is closed with the piston 32a of the fluid lead-in / out means 32 of the detection unit 34 pushed out in advance. A certain amount of drain oil is stored in the reservoir portion 69 and the second reservoir portion 70, and the drain oil of the second reservoir portion 70 is led in and out using the fluid lead-in / out means 32. As in the example, the concentration of the magnetic material is measured.

  As described above, according to the third example of the embodiment, substantially the same operational effects as the first example can be obtained. In the third example of the embodiment, the reservoir includes a first reservoir 69 for storing an old fluid and a second reservoir 70 for receiving and storing a new fluid. When connected to the reservoir 70, a new drain oil fluid is introduced into the detector 34 by the fluid lead-in / out means 32, so that the old fluid and the new fluid are prevented from being mixed and the concentration of the magnetic substance in the fluid is continuously increased. Can be measured accurately. Further, since the first reservoir 69 and the second reservoir 70 together with the arrangement of the detector 34 suitably prevent air from being mixed into the fluid, the concentration of magnetic powder in the fluid is continuously and extremely accurate. It can be measured.

  In addition, the magnetic substance concentration measuring apparatus and the magnetic substance concentration measuring method of the present invention are not limited only to the above-described embodiments. The magnetic substance concentration is continuously measured to eliminate the influence of disturbance and changes with time. If it does, it is not limited to a form example, Other configurations and signal processing may be used, the fluid is not limited to drain oil, and other oil, aqueous solution, water, powder, etc. may be used. The means is not limited as long as the difference between the signal of the processing step at the time of introducing the fluid and the signal of the processing step at the time of discharging the fluid can be obtained, and other processing means may be used. Of course, the lead-in / out means may be an eccentric rotator instead of the piston, and various modifications can be made without departing from the scope of the present invention.

It is a conceptual diagram which shows the 1st example of embodiment of this invention. It is a conceptual diagram which shows another example in the 1st example of embodiment of this invention. It is a block diagram which shows the structure of the fluid extraction / introduction means and signal processing part in embodiment of this invention. It is a block diagram of the other example which shows the structure of the fluid extraction / introduction means and signal processing part in embodiment of this invention. It is a conceptual diagram which shows the process from an output signal to the output value (DC voltage signal) for a comparison in the state which does not have the influence of a magnetic body. It is a conceptual diagram which shows the process from an output signal to the output value (DC voltage signal) for the density | concentration of a magnetic body in the state which has the influence of a magnetic body. It is a flowchart which calculates | requires the density | concentration etc. of a magnetic body (inspection object), and determines the sliding state of a sliding object. It is a graph which shows the detection state at the time of actually measuring a test object. It is the schematic which shows the 2nd example of embodiment of this invention. It is a block diagram which shows the structure of the fluid extraction / introduction means and signal processing part in the 2nd example of embodiment of this invention. It is a block diagram of the other example which shows the structure of the fluid extraction / introduction means and signal processing part in the 2nd example of embodiment of this invention. It is the schematic which shows the 3rd example of embodiment of this invention.

Explanation of symbols

1 channel 2 fluid lead-in / out means (drive means)
2a Piston 3 Detection means 4 Detection section 5 Signal processing device 6 Signal processing section (measurement means)
7 Measurement value display and abnormality determination device (warning means)
11 Coil 11a Excitation coil 11b Detection coil (Output coil)
11c Excitation coil 11d Detection coil (Output coil)
14 Sine wave oscillation circuit (oscillation circuit)
Reference Signs List 31 Flow path 32 Fluid lead-in / out means 32a Piston 33 Detection means 34 Detection section 35 Lock-in amplifier 36 Signal processing section 37 Measurement value display and abnormality determination device (warning means)
46 Coil 46a Excitation coil 46b Detection coil (Output coil)
49 Sine wave oscillator (oscillator)
61 Flow path 70 Second reservoir

Claims (24)

  A magnetic substance concentration measuring device comprising an excitation coil and an output coil that generates an excitation voltage when an alternating current flows through the excitation coil, wherein the voltage of the excitation coil and the voltage of the output coil Measuring means for measuring the change in phase difference between them, and grasping the concentration of the magnetic material from the change in phase difference generated when the inspection object is brought close to the excitation coil and / or the output coil A magnetic substance concentration measuring device.   2. The magnetic substance concentration measuring apparatus according to claim 1, wherein a lock-in amplifier is used as the measuring means.   3. The magnetic substance concentration measuring apparatus according to claim 2, wherein a voltage of the exciting coil is used as a reference signal for the lock-in amplifier.   As means for bringing the inspection object close to the exciting coil and / or the output coil, driving means for introducing the inspection object from a flow path through which the fluid containing the magnetic body flows or a reservoir in which the fluid containing the magnetic body accumulates. The magnetic substance concentration measuring apparatus according to claim 1, wherein the magnetic substance concentration measuring apparatus is provided.   A flow path through which a fluid containing magnetic material flows, or a detection section that is connected to a reservoir section in which fluid containing the magnetic body is accumulated to provide fluid lead-in / out means and detection means; and a lock-in amplifier connected to the detection means A signal processing unit arranged, wherein the detection unit derives and introduces the fluid by the fluid introduction / extraction means and detects the detection signal of the magnetic substance at the time of fluid introduction from the output signal of the AC voltage via the detection unit and The correction processing signal is acquired, and the signal processing unit removes noise from each signal by a lock-in amplifier using a reference signal having the same frequency and simultaneously detects a phase difference between each signal and the reference signal. Then, the magnetic substance concentration measuring apparatus is configured to convert the converted value into a DC voltage signal according to the detected amount of phase difference, and to detect the difference between the converted values as the concentration of the magnetic substance.   A flow path through which a fluid containing magnetic material flows, or a detection section that is connected to a reservoir section in which fluid containing the magnetic body is accumulated to provide fluid lead-in / out means and detection means; and a lock-in amplifier connected to the detection means A signal processing unit arranged, wherein the detection unit extracts a fluid detection signal when the fluid is introduced and fluid is introduced by the fluid introduction / extraction unit, and a correction detection signal when the fluid is discharged via the detection unit. The signal processing unit obtains noise from each signal by a lock-in amplifier using a reference signal having the same frequency, converts the signal into a DC voltage signal, and converts the difference between the converted values to the concentration of the magnetic material. A magnetic substance concentration measuring device configured to detect as:   The signal processing unit is configured to shift a phase of a reference signal or a phase of a detection signal of a magnetic material so that a value obtained by converting an output signal into a DC voltage signal is close to zero when the magnetic material is not detected. The magnetic substance concentration measuring device according to claim 5 or 6.   The detection means includes an output coil for obtaining a detection signal of a magnetic material, and an excitation coil, and an AC voltage is applied to the excitation coil to generate an output signal of the AC voltage in the output coil. 7. The configuration according to claim 5, wherein a detection signal for magnetic substance or a detection signal for correction is obtained from the output signal, and a reference signal is obtained from an oscillation circuit connected to the excitation coil. The magnetic substance concentration measuring apparatus described.   The detection means is configured such that a plurality of excitation coils are wound in opposite directions and the detection coil is disposed between the plurality of excitation coils so that the output signal of the detection coil is reduced. The magnetic substance concentration measuring apparatus according to claim 5, wherein the magnetic substance concentration measuring apparatus is a magnetic substance concentration measuring apparatus according to claim 5.   The magnetic substance concentration measuring device according to claim 5 or 6, wherein the fluid lead-in / out means is configured to lead in / out the fluid by a reciprocating motion of a piston.   From a test object containing a magnetic substance or a fluid containing a magnetic substance, at least one of the concentration of the magnetic substance, the change rate of the density, the amplitude of the density change, the period of the density change, and the concentration deviation during multipoint measurement The information is obtained, and the state of the sliding object is determined from the correlation between the magnetic substance concentration obtained in advance and the state of the sliding object. Magnetic substance concentration measuring device.   12. The magnetic substance concentration measuring device according to claim 11, further comprising warning means for issuing a warning or / and a warning according to the state of the sliding object.   The lubricating fluid supply amount, the supply timing, the supply pressure, the supply temperature, the lubricating fluid injection method, and the properties of the lubricating fluid are controlled in accordance with the state of the sliding object. 11. The magnetic substance concentration measuring apparatus according to 11.   A magnetic substance concentration measurement method using an excitation coil and an output coil that generates an excitation voltage when an alternating current flows through the excitation coil, the inspection object and the excitation coil or / and the output coil And measuring the change in phase difference between the voltage of the exciting coil and the voltage of the output coil when approaching each other, and grasping the concentration of the magnetic material, .   The magnetic substance concentration measuring method according to claim 14, wherein a phase difference of the voltage signal of the output coil is partially inverted and converted into a direct current to measure a change in phase difference.   The magnetic substance concentration measuring method according to claim 14 or 15, wherein a phase of the voltage signal of the output coil is partially inverted using a voltage signal of the excitation coil.   15. The inspection object is introduced from a flow path through which a fluid containing a magnetic body flows or a reservoir portion in which a fluid containing a magnetic body is accumulated, and is brought close to the exciting coil and / or the output coil. The magnetic substance density | concentration measuring method in any one of -16. The fluid is introduced from the flow path through which the fluid containing the magnetic material flows or the reservoir containing the fluid containing the magnetic material to the detection unit, and the detection signal of the magnetic material is acquired from the fluid of the detection unit and the reference signal of the same frequency is obtained. At the time of introducing a fluid that is prepared and processed so that the detection signal of the magnetic substance and the reference signal of the same frequency are combined to remove noise by a lock-in amplifier and converted to a DC voltage signal as an output value for the concentration of the magnetic substance Processing steps of
The fluid is discharged from the detection unit, the detection signal for correction in the detection unit is acquired, and a reference signal having the same frequency is prepared, and noise is removed by a lock-in amplifier by combining the detection signal for correction and the reference signal of the same frequency. And a processing step at the time of fluid discharge processed so as to be converted into a DC voltage signal as an output value for comparison,
A magnetic substance concentration measuring method, wherein an output value for concentration of the magnetic substance is corrected by the output value for comparison.   In the processing step at the time of introducing the fluid and the processing step at the time of discharging the fluid, the detection signal of the magnetic material and the detection signal for correction are obtained from the output signal of the alternating voltage, and the detection signal of the magnetic material and the detection signal for correction have the same frequency. At the same time, noise is removed from each signal by a lock-in amplifier together with the reference signal, and at the same time, the phase difference between each signal and the reference signal is detected. 19. The magnetic substance concentration measuring method according to claim 18, wherein the magnetic substance concentration measuring method is converted into an output value and an output value for comparison.   By alternately and alternately repeating the treatment process at the time of fluid introduction and the treatment process at the time of fluid discharge, the difference is further converted into a DC voltage signal from the output value for the concentration of the magnetic substance and the output value for comparison. 20. The magnetic substance concentration measuring method according to claim 18 or 19, wherein the difference is converted into a magnetic substance concentration according to a correlation obtained in advance to eliminate a measurement error due to a disturbance or a change with time.   The phase of the reference signal or the detection signal of the magnetic material is shifted, and the value obtained by converting the output signal of the signal processing device into a DC voltage signal is brought close to zero. Magnetic substance concentration measurement method.   From a test object containing a magnetic substance or a fluid containing a magnetic substance, at least one of the concentration of the magnetic substance, the change rate of the density, the amplitude of the density change, the period of the density change, and the concentration deviation at the time of multipoint measurement. The magnetic substance concentration measurement according to any one of claims 18 to 21, wherein information is obtained, and the state of the sliding object is determined from a correlation between the magnetic substance concentration obtained in advance and the state of the sliding object. Method.   23. The magnetic substance concentration measuring method according to claim 22, wherein a warning or / and a warning are issued according to the state of the sliding object. 23. The lubrication fluid supply amount, supply timing, supply pressure, supply temperature, lubrication fluid injection method, and lubrication fluid properties to the slide are controlled according to the state of the slide. Magnetic substance concentration measurement method.

Images