JP2005106017A - Oil mist concentration detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil mist concentration detection device enabling a reduction in installation space and having excellent durability and reliability. <P>SOLUTION: Oil mist sensors 3 are fixed to cylinders 2 with the insertion parts of six oil mist sensors 3 inserted into six cylinders of a six-cylinder engine 1 which are the source of oil mist. Signals indicating the oil mist concentration of the cylinders 2 detected by an optical detection part 8 and signals indicating the output of the light emitting element of the optical detection part 8 are transmitted to a controller 10 through a first wiring 5 and a second wiring 6. Based on these signals, the oil mist concentration correction part of the controller 10 corrects the concentration of the oil mist for each cylinder 2, an abnormality determination part determines for each oil mist sensor 3 whether mechanical defect is present or not in the source of the oil mist, and a trouble determination part determines for each oil mist sensor 3 whether a trouble is present or not. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an oil mist concentration detection device.

  Generally, in an internal combustion engine, an oil that constantly monitors the oil mist concentration in the crankcase and issues an alarm if the oil mist concentration exceeds a predetermined value in order to prevent damage to the internal combustion engine or a serious accident due to bearing overheating or the like. A mist concentration detection device is provided.

  For example, as such an oil mist concentration detection device, there is one using the concentration detection device described in FIG. 4 of Japanese Patent No. 3205172 (Patent Document 1).

  This oil mist concentration detection device connects each pipe inserted into each of a plurality of crankcases of a multi-cylinder engine and the intake port of the oil mist concentration detection device at regular intervals using a rotary valve. Then, by the gas suction mechanism of the oil mist concentration detection device, the atmosphere containing the oil mist of each crankcase is drawn into the oil mist detection unit of the oil mist concentration detection device at regular intervals, and Oil mist concentration is detected.

  However, in this oil mist concentration detection device, the pipe that guides the atmosphere containing the oil mist in the crankcase to the outside of the crankcase, and each pipe and the intake port of the oil mist concentration detection device at regular intervals. Since a gas suction mechanism is required to draw the atmosphere including the oil mist of the rotary valve to be connected to each crankcase into the oil mist detector of the oil mist concentration detector, a large space is required and the oil mist concentration There exists a problem that a detection apparatus is complicated and enlarges.

Further, in the oil mist concentration detection device, the pipe, the gas suction mechanism, and the rotary valve have mechanically movable parts that are likely to deteriorate, so the durability of the oil mist concentration detection device is low. There is a problem that the reliability of the detected oil mist concentration value decreases with the passage of time.
Japanese Patent No. 3205172 (Fig. 4)

  Therefore, an object of the present invention is to provide an oil mist concentration detection device that can reduce the installation space and is excellent in durability and reliability.

In order to solve the above problems, the oil mist concentration detection device of the present invention is:
A plurality of oil mist sensors having an optical detection unit for detecting oil mist and outputting a signal representing the oil mist concentration;
An oil mist concentration that is connected to the plurality of oil mist sensors through a communication path and corrects a signal representing each oil mist concentration from each oil mist sensor based on a plurality of signals output from each oil mist sensor. A correction unit, an abnormality determination unit for determining whether the oil mist concentration is a value indicating an abnormality of a source machine based on a signal representing each oil mist concentration corrected by the oil mist concentration correction unit, and each oil And a controller having a failure determination unit that determines failure of the mist sensor.

  The signal representing the oil mist concentration is, for example, a signal obtained by converting the light emitted from the light emitting element of the optical detection unit through the atmosphere containing the oil mist, receiving the light at the light receiving element, and converting the current. Alternatively, the light emitted from the light emitting element of the optical detection unit is a signal that is scattered in an atmosphere containing oil mist, received by the light receiving element, and converted into a current. In this way, the oil mist concentration can be measured by the amount of light received by the light receiving element.

  In addition to the signal representing the oil mist concentration, a signal representing the light amount of the light emitting element may be employed as the plurality of signals. In this case, the deterioration of the light emitting element can be known by measuring the light amount of the light emitting element. Further, when the light quantity of the light emitting element is normal and the signal indicating the oil mist concentration is smaller than necessary, it can be determined that the optical detection unit is dirty.

  In addition to the signal representing the oil mist concentration, a signal having an oil mist concentration of zero in the atmosphere may be employed as the plurality of signals. In this case, a signal having an oil mist concentration of zero represents information that combines the deterioration of the light emitting element and the effect of contamination of the optical detection unit.

  Further, the above correction indicates correction of dirt on the optical detection unit.

  According to the oil mist concentration detection device of the above invention, after each of the plurality of oil mist sensors detects each oil mist concentration in a plurality of atmospheres, a plurality of signals including a signal indicating the oil mist concentration are wired or The controller that outputs the signal to the controller via a wireless communication channel and receives the plurality of signals represents the concentration of each oil mist from each of the oil mist sensors based on the plurality of signals. Since the signal is corrected, it is possible to omit complicated piping for guiding the atmosphere including oil mist, which has been conventionally required, to the outside of the oil mist source. Therefore, the installation space of the oil mist concentration detection device can be greatly reduced, and the internal combustion engine having the oil mist concentration detection device can be made compact.

  In addition, according to the oil mist concentration detection apparatus of the present invention, the oil mist concentration can be calculated without using equipment having a mechanically movable part such as a pipe, a gas suction mechanism, and a rotary valve that is easily deteriorated. Therefore, the oil mist concentration detection device can be made excellent in durability and reliability.

  In the oil mist concentration detection device according to an embodiment, the failure determination unit calculates an average value of the plurality of oil mist concentrations corrected by the oil mist concentration correction unit, and the average value and the plurality of oil mists are calculated. It is characterized in that a failure of each oil mist sensor is determined by comparing the concentrations with each other.

  According to the embodiment, the failure determination unit calculates an average value of the plurality of oil mist concentrations corrected by the oil mist concentration correction unit, and compares the average value with the plurality of oil mist concentrations. Therefore, for example, the oil mist sensor corresponding to an oil mist concentration that has a large deviation from the above average and a value that is extremely small compared to other oil mist concentrations is determined. Can be determined. The oil mist sensor determined to be a failure by the failure determination unit is excluded from the subsequent calculation of the average value, and can also be excluded from the calculation of the average value by presetting with the controller.

  The oil mist concentration detection apparatus according to an embodiment includes an oil mist concentration display unit that displays the oil mist concentration corrected by the oil mist concentration correction unit, and an oil mist sensor that the failure determination unit determines as a failure. The failure oil mist sensor display unit for displaying the error, the oil mist concentration corrected by the oil mist concentration correction unit is an abnormality determination unit for determining whether the oil mist concentration is a value indicating an abnormality of the machine of the generation source, and the abnormality determination unit A first alarm unit that issues an alarm when the oil mist concentration is a value that indicates an abnormality of the machine that is the oil mist generation source of the oil mist generation source, and the failure determination unit determines that a failure has occurred The second alarm unit that issues an alarm when the generated oil mist sensor is generated and continues the alarm, and the signal from the oil mist sensor And a data storage unit that stores at least one of the oil mist concentration data corrected by the oil mist concentration correction unit and the determination data of the failure determination unit, and the output signal of the oil mist concentration correction unit and the above It is characterized by including at least two of communication units that output at least one of the output signals of the failure determination unit to an external device.

  The communication unit may be for transmitting oil mist concentration and oil mist concentration failure data to an external output unit as a relay means. It may be for transmitting the failure data.

  According to the embodiment, the controller displays an oil mist concentration display unit that displays the oil mist concentration corrected by the oil mist concentration correction unit, and a failed oil mist that displays the oil mist sensor that the failure determination unit has determined to be a failure. The sensor display unit, the oil mist concentration corrected by the oil mist concentration correction unit, an abnormality determination unit for determining whether the oil mist concentration is a value indicating an abnormality of the machine of the generation source, and the oil mist concentration in the abnormality determination unit A first alarm unit that issues an alarm when the value is indicative of an abnormality of the machine that is the source of the occurrence of an oil mist sensor that has been determined as a failure by the failure determination unit, A second alarm unit that maintains an alarm, signal data from the oil mist sensor, and oil mist corrected by the oil mist concentration correction unit A data storage unit that stores at least one of the concentration data and the determination data of the failure determination unit, and at least one of an output signal of the oil mist concentration correction unit and an output signal of the failure determination unit to an external device Since at least two of the output communication units are provided, a convenient and versatile oil mist concentration detection device can be constructed.

  According to the oil mist concentration detection apparatus of the present invention, after detecting each oil mist concentration in a plurality of atmospheres with a plurality of oil mist sensors, a plurality of signals including a signal representing the oil mist concentration are transmitted by wired or wireless communication. An atmosphere containing oil mist, which has been necessary in the past, is output to the controller via the road and the correction unit of the controller that receives the plurality of signals corrects each oil mist concentration in the plurality of atmospheres. The complicated piping for guiding the oil mist to the outside of the oil mist source can be omitted, the installation space of the oil mist concentration detecting device can be greatly reduced, and the internal combustion engine having the oil mist concentration detecting device can be made compact.

  In addition, according to the oil mist concentration detection apparatus of the present invention, the oil mist concentration can be calculated without using equipment having a mechanically movable part such as a pipe, a gas suction mechanism, and a rotary valve that is easily deteriorated. Therefore, the oil mist concentration detection device can be made excellent in durability and reliability.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing an oil mist concentration detection device according to an embodiment of the present invention applied to a 6-cylinder engine 1.

  This oil mist concentration detection device includes six oil mist sensors 3, five first wirings 5 and one second wiring 6 constituting a communication path, and a controller 10.

  Each of the six oil mist sensors 3 includes two input / output terminals 12, an optical detection unit 8, and a correction unit (not shown). Each of the optical detectors 8 can adjust sensitivity. In the oil mist sensor 3, the portion where the atmosphere containing oil mist enters is inserted one by one into the six cylinders 2 of the six-cylinder engine 1. The correction unit corrects the temperature characteristics of the sensor whose temperature is detected by the thermistor to the output signal from the optical detection unit 8 and linearizes the corrected signal.

  The first wiring 5 connects between two adjacent oil mist sensors 3 of the six oil mist sensors, and the second wiring 6 is located at the right end of the six oil mist sensors in the figure. The oil mist sensor 6 and the controller 10 are connected. One end of the second wiring 6 is connected to the input / output terminal 12 of the oil mist sensor 6 at the right end in the drawing, and the other end of the second wiring 6 is connected to the input / output terminal 7 of the controller.

  The controller 10 includes an oil mist concentration correction unit (not shown), an abnormality determination unit (not shown), and a failure determination unit (not shown).

  The oil mist concentration correction unit receives signals representing the oil mist concentration of the atmosphere in each cylinder 6 from the six oil mist sensors 3 via the first wiring 5 and the second wiring 6, and the optical detection unit 8. When a signal representing the output of the light emitting element is received, in each of the six cylinders 6, the effect of dirt on the optical detection unit is corrected to the signal representing the oil mist concentration, and the oil mist concentration is calculated for each cylinder 6. It is like that.

  In addition, the abnormality determination unit includes the oil mist concentration for each cylinder 6 corrected by the oil mist concentration correction unit, and the oil mist concentration generation source machine in each cylinder 6 preset for each cylinder 6. Whether or not the oil mist concentration for each cylinder 6 corrected by the oil mist concentration correction unit is a value indicating an abnormality in the machine of the source by comparing with the lower limit oil mist concentration when a failure occurs. Is judged.

  The failure determination unit calculates an average value of the oil mist concentration for each cylinder 6 corrected by the oil mist concentration correction unit, and calculates a difference between the average value and the oil mist concentration for each cylinder 6. The variation from the average value is calculated for each cylinder 6. The oil mist sensor 3 corresponding to the oil mist concentration whose difference is larger than a predetermined value and whose value is extremely smaller than other oil mist concentrations is determined to be a failure.

  FIG. 2 is a side view of the oil mist sensor 3 showing the detailed structure of the oil mist sensor 3.

  As shown in FIG. 2, the oil mist sensor 3 includes an insertion portion 21, a screw portion 25, and a signal transmission / reception portion 27.

  Inside the insertion portion 21, an atmosphere intrusion portion in an optical detection portion (not shown) is provided. Further, the insertion portion 21 is provided with three round holes 20 for convenience one by one on the lower surface in the vertical direction and on both side surfaces. The oil mist sensor 3 detects the oil mist concentration based on the atmosphere containing the oil mist that naturally diffuses through the three round holes 20 and reaches the optical detection unit.

  The oil mist sensor 3 is not provided with a round hole on the upper surface, but this is because dirt such as an oil enemy tends to adhere to the upper surface. This is because dirt enters the inside of the insertion portion 21 through the round hole on the upper surface, and accurate measurement cannot be performed. Needless to say, the shape, location and number of holes for taking in the atmosphere are not limited.

  The screw portion 25 is screwed with a screw portion formed on a side surface of the cylinder (shown by 2 in FIG. 1), and the oil mist sensor 3 has the insertion portion 21 inserted into the cylinder. In such a state, the cylinder is fixed to the cylinder so that the direction does not change.

  The signal transmitting / receiving unit 27 includes two input / output terminals 12 and can transmit and receive data between adjacent oil mist sensors 3 and between the oil mist sensor 3 and the controller 10 as described above. It is like that.

  The signal transmitted from the controller 10 to the oil mist sensor 3 includes a signal indicating the installation sensitivity of the optical detection unit based on the dirt of each optical detection unit 8 obtained by the oil mist concentration correction unit.

  Although not described in detail, as shown in FIG. 2, each of the first wiring 5 and the second wiring 6 includes a data transmission wiring and a data reception wiring, and the second wiring 6. The data transmission wiring and the data reception wiring are branched on the controller 10 side and connected to the input / output terminal 7 of the controller 10.

  FIG. 3 is a front view of the controller 10 provided in the oil mist concentration detection device of this embodiment.

  In addition to the oil mist concentration correction unit, the abnormality determination unit, and the failure determination unit, the controller 10 constitutes an oil mist concentration display unit 33 and a first alarm unit as shown in FIG. As an example of a first alarm device (not shown) and a first alarm display unit 35, a second alarm device (not shown) and a second alarm display unit 37 constituting a second alarm unit, and a communication unit An input / output terminal 31 and a data storage unit (not shown) are provided.

  The oil mist concentration display unit 33 has a configuration in which 16 rows of level meters each including 16 LEDs are provided. Each column of the level meter corresponds to a different oil mist sensor, and the controller 10 can display detection results of up to 16 oil mist sensors.

  The level meter displays the oil mist concentration corrected by the oil mist concentration correction unit. Specifically, there is a correspondence between each LED of the level meter and the oil mist concentration corrected by the oil mist concentration correction unit, and as the oil mist concentration corrected by the oil mist concentration correction unit increases. The upper LEDs are sequentially turned on. In this embodiment, the oil mist concentration difference between the LEDs adjacent in the vertical direction is set to a constant and predetermined concentration difference.

  In the level meter, the oil mist concentration value indicated by the 16th LED is set in advance to the lower limit oil mist concentration value when an abnormality in the machine that is the source of the oil mist (such as bearing seizure) occurs. This level meter checks the uppermost LED that is lit on each level meter, thereby determining the oil mist concentration of the oil mist source corresponding to this level meter, It is possible to specify a concentration that is equal to or higher than the mist concentration and that is smaller than the concentration obtained by adding the oil mist concentration difference to the reference oil mist concentration. When the 16th LED is lit, it is possible to determine the abnormality of the oil mist generating machine corresponding to the lit level meter.

  In this level meter, the 8th LED from the bottom of the 16 LEDs emits green, and the 9th to 11th LEDs emit orange. The 12th to 16th LEDs emit red light. In this way, when the 11th LED is lit, attention is urged, and by checking whether the 16th LED is lit, it is determined whether or not the oil mist generating machine is abnormal. It can be easily determined.

  When the 16th LED is turned on for at least one oil mist source, the first alarm device of the first alarm unit issues an alarm and the first alarm display unit 35 of the first alarm unit. Lights up in red and the alarm continues. In addition, when the failure determination unit of the controller 10 determines a failure of the oil mist sensor in at least one oil mist source, the second alarm device of the second alarm unit issues an alarm and the second The second alarm display unit 37 of the alarm unit is lit red to keep the alarm.

  Wiring is connected to the input / output terminal 31 so that the oil mist concentration and the information of the failed oil mist sensor can be output to an external device such as a repeater or a monitor.

  The data storage unit stores input data from the oil mist sensor, oil mist concentration data corrected by the oil mist concentration correction unit, determination data of the abnormality determination unit, and failure determination unit. In this way, accumulation of data necessary for correction by the oil mist concentration correction unit, accumulation of data of changes over time in the oil mist concentration for each oil mist source, and the like can be performed.

  Note that the display unit 34 in FIG. 3 is lit in orange when the eleventh LED of at least one level meter is lit, so as to call attention. The display unit 36 is lit in green when no sensor failure has occurred and the oil mist concentration detection device is operating normally.

  FIG. 4 is a view showing a flowchart of the operation of the oil mist concentration apparatus of this embodiment.

  Hereinafter, a rough flow of the operation of the oil mist concentration apparatus will be described with reference to FIG.

First, the detection of the oil mist gas concentration by the optical detection unit of the oil mist sensor and the detection of the output of the light emitting element of the optical detection unit are performed in step S1. In step S2, the correction unit of the oil mist sensor corrects the temperature characteristics of the sensor detected by the thermistor to the output signal from the optical detection unit, and linearizes the signal after correction. In the next step S3, analog data from the correction unit of the oil mist sensor is converted into digital data by the A / D conversion unit, and this digital data is stored in the data storage unit. Then, in response to a request from the communication unit of the controller 10, in the next step S4, the latest digital signal (digital data) having a predetermined data length is transmitted from the communication unit of the oil mist sensor via the communication path. To the output. The oil mist sensor is set to continuously transmit the oil mist concentration data and the output data of the light emitting element to the controller by repeating the operations of S1 to S4.

  Step S5 is a process in which the controller receives a digital signal from the oil mist sensor. The digital signal received in this process is accumulated in the data storage unit until data from a plurality of oil mist sensors connected to the controller 10 through a communication path is collected in the next step S6. When the above data is collected, the data accumulated in the data storage unit of the controller 10 is transmitted to the oil mist concentration correction unit of the controller 10.

  In the next step S7, the oil mist concentration correction unit that has received the signal from the data storage unit corrects the effect of contamination of the optical detection unit to the signal representing the oil mist concentration, and the oil mist concentration for each cylinder. Is calculated.

  Next, in step S8, the oil mist concentration for each cylinder corrected by the oil mist concentration correction unit is displayed on the oil mist concentration display unit.

  In the next step 9, the failure determination unit that receives the signal from the oil mist concentration correction unit calculates the average value of the oil mist concentration for each cylinder corrected by the oil mist concentration correction unit, and calculates the average value and The difference from the oil mist concentration for each cylinder is calculated, and the variation from the average value is calculated for each cylinder. An oil mist sensor corresponding to an oil mist concentration whose difference is larger than a predetermined value and whose value is extremely smaller than other oil mist concentrations is determined to be a failure. When the failure determination unit determines that there is no failure of the oil mist sensor in all the sensors as indicated by NO in step S10, the process directly returns to step S5 in which the signal from the sensor is received. Yes. On the other hand, when the failure determination unit determines that a failure has occurred with respect to at least one oil mist sensor, as indicated by YES in step S10, the process proceeds to step S11 and the second alarm unit is activated. The process returns to step S5.

  According to the oil mist concentration detection device of the above embodiment, after detecting the oil mist concentration in the cylinder 6 by the optical detection unit 8 of the oil mist sensor 3, the electric signal representing the oil mist concentration as an example of a plurality of signals; A signal representing the output of the light emitting element of the optical detection unit 8 is output to the controller 10 via the communication path including the first wiring 5 and the second wiring 6, and the controller 10 has the inside of each of the six cylinders 2. Therefore, the complicated piping for guiding the atmosphere including the oil mist required conventionally to the outside of the oil mist source can be omitted. Therefore, the installation space of the oil mist concentration detection device can be greatly reduced, and the internal combustion engine having the oil mist concentration detection device can be made compact.

  Further, according to the oil mist concentration detection device of the above embodiment, since the oil mist concentration is detected without using a pipe, a gas suction mechanism, a device having a mechanically movable part such as a rotary valve, which is easily deteriorated, The oil mist concentration detection device can be made excellent in durability and reliability.

  Further, according to the oil mist concentration detection device of the above embodiment, the failure determination unit calculates the average oil mist concentration in each cylinder 6 corrected by the oil mist concentration correction unit, and the oil mist in each cylinder 6. Since the concentrations are compared, it is possible to determine that the oil mist sensor 3 corresponding to an oil mist concentration corresponding to an oil mist concentration having a large deviation from the above average and an extremely small value compared to other oil mist concentrations is a failure.

  Further, according to the oil mist concentration detection device of the above embodiment, the controller 10 determines whether the oil mist concentration corrected by the oil mist concentration display unit 33 and the oil mist concentration correction unit is a value indicating an abnormality in the machine of the generation source. When the oil mist concentration is a value indicating the abnormality of the machine that is the source of the oil mist, the first alarm unit that continues to generate an alarm and the failure determination unit fails. When the determined oil mist sensor 3 is generated, a second alarm unit that issues an alarm and maintains this alarm, a data storage unit that accumulates and stores input data from the oil mist sensor 3, and an external device Since the input / output terminal 31 is provided as an example of an output communication unit, a convenient and versatile oil mist concentration detection device can be constructed.

  In the oil mist concentration detection device of the above embodiment, the controller 10 has various functions. However, in the oil mist concentration detection device of the present invention, the controller is at least an oil mist concentration that corrects the oil mist concentration. What is necessary is just to have the correction | amendment part, the abnormality determination part which determines abnormality of the machine of the generation source of oil mist, and the failure determination part which determines the failure of an oil mist sensor. An input / output terminal is provided according to the application, and the oil mist concentration data and the oil mist sensor failure data are transmitted to the external output unit as a relay means and the monitor device via the input / output terminal. You may do it.

  In the oil mist concentration detection device of the above embodiment, the failure oil mist concentration display unit for individually displaying the failed oil mist sensor is not formed. However, in the oil mist concentration detection device of the present invention, the controller In addition, a faulty oil mist concentration display unit for displaying the faulty oil mist sensor may be formed.

  In the oil mist concentration detection device of the above embodiment, data is exchanged using the five first wires 5 and one second wire 6, but in the oil mist concentration detection device of the present invention, For example, a communication line other than a communication line using five first wires 5 and one second wire 6, such as each sensor and controller being independently connected by six wires to exchange data. You may also exchange data.

  In the oil mist concentration detection device of the above embodiment, the data exchange between the oil mist sensor 3 and the controller 10 is performed through the first wiring 5 and the second wiring 6 which are wired. In the oil mist concentration detection device, data exchange between the oil mist sensor and the controller may be performed through a wireless communication path using an antenna or the like. In this case, the installation space for the oil mist concentration detection device is further increased. Can be small.

  In the oil mist concentration detection device of the above embodiment, the oil mist concentration detection device is applied to a 6-cylinder engine. However, the oil mist concentration detection device of the present invention may be applied to a 12-cylinder engine. Further, the oil mist concentration detecting device of the present invention may be applied to any engine as long as it has an engine having a plurality of oil mist sources.

It is a schematic diagram of the oil mist density | concentration detection apparatus of one Embodiment of this invention. It is a figure which shows the detailed structure of the oil mist sensor with which the oil mist density | concentration detection apparatus of the said embodiment is provided. It is a front view of the display part of the controller with which the oil mist density | concentration detection apparatus of the said embodiment is provided. It is a figure which shows the flowchart of operation | movement of the oil mist concentration apparatus of this embodiment.

Explanation of symbols

2 cylinder 3 oil mist sensor 5 first wiring 6 second wiring 7, 12, 31 input / output terminal 8 optical detection unit 10 controller 33 oil mist concentration display unit 35 first alarm display unit 37 second alarm display unit

Claims (3)

A plurality of oil mist sensors having an optical detection unit for detecting oil mist and outputting a signal representing the oil mist concentration;
An oil mist concentration that is connected to the plurality of oil mist sensors through a communication path and corrects a signal representing each oil mist concentration from each oil mist sensor based on a plurality of signals output from each oil mist sensor. A correction unit, an abnormality determination unit for determining whether the oil mist concentration is a value indicating an abnormality of a source machine based on a signal representing each oil mist concentration corrected by the oil mist concentration correction unit, and each oil An oil mist concentration detection apparatus comprising: a controller having a failure determination unit that determines failure of a mist sensor. In the oil mist concentration detection apparatus according to claim 1,
The failure determination unit calculates an average value of a plurality of oil mist concentrations corrected by the oil mist concentration correction unit, and compares each of the average values with the plurality of oil mist concentrations to thereby determine each oil mist sensor. An oil mist concentration detection device characterized by determining a failure of the oil. In the oil mist concentration detection apparatus according to claim 1 or 2,
The controller includes an oil mist concentration display unit that displays an oil mist concentration corrected by the oil mist concentration correction unit, a failure oil mist sensor display unit that displays an oil mist sensor that the failure determination unit has determined to be a failure, and the oil mist An abnormality determination unit that determines whether the oil mist concentration corrected by the concentration correction unit is a value indicating an abnormality of the machine that is the source of the generation. A first alarm unit that issues an alarm at a certain time and maintains the alarm; a second alarm unit that generates an alarm and maintains the alarm when an oil mist sensor determined by the failure determination unit as a failure occurs; Signal data from the oil mist sensor, oil mist concentration data corrected by the oil mist concentration correction unit, and determination data of the failure determination unit At least two of a data storage unit that stores at least one of the output unit and a communication unit that outputs at least one of an output signal of the oil mist concentration correction unit and an output signal of the failure determination unit to an external device. An oil mist concentration detection device comprising:

Images