JP2678136B2 - Oil mist alarm device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil mist alarm device for causing an oil mist in each crank chamber of a diesel engine or the like to sequentially flow into a photoelectric tube and issuing an alarm when the concentration of the oil mist exceeds a certain value.

[0002]

2. Description of the Related Art Conventionally, an oil mist alarm device of this type is known, for example, as shown in FIG. This alarm device connects all the 10 inlet ports provided in the casing 52 of the rotary valve 51 except the 0th port to each crank chamber (not shown) of the diesel engine, and has an AC motor and a reduction gear (not shown). The inlet port is sequentially switched to the outlet port 54 by the passage in the valve body 53 which is driven to rotate intermittently via the Geneva gear mechanism. Further, the inlet holes 55a, 55a of the photoelectric tube 55 having the tungsten lamp 56 as a light source at one end and the photocell 57 as a light receiving element at the other end are connected to the outlet port 54 of the rotary valve 51, while the outlet hole of the photoelectric tube is connected. The blower 58 is connected to 55b, the blower 58 and the bypass port 59 of the rotary valve 51 are connected by a bypass pipe 60, and the oil mist from each crank chamber is indicated by an arrow in the figure through an inlet port which is connected for switching. As shown, the blower 58 sucks into the phototube 55, while the oil mist at the other inlet port continues suction while bypassing the phototube. The output voltage of the photocell 57 is a constant value (alarm set value) due to the high concentration oil mist.
When the following occurs, an alarm lamp is turned on by a control unit (not shown) and rotation of the valve body 53 of the rotary valve is stopped so that the crank chamber number in which the mist abnormality has occurred can be confirmed.

Further, lenses 61, 6 in front of the tungsten lamp 56 and the photocell 57 are formed by oil mist.
In order to prevent 1 from being fogged, the front of both lenses is partitioned, and the outside air is supplied to this by the pump 62 to form an air curtain chamber, and the 0th port released to the atmosphere at each rotation of the valve body 53 is provided. After that, fresh air is flown into the photoelectric tube 55. Further, since a slight drop in the output voltage of the photocell 57 cannot be avoided due to clouding due to mist adhesion of the lens during long-term use, the user periodically stops the valve body 53 at the 0th port position, The zero adjustment knob is turned while flowing fresh air to adjust the zero point of the photocell output.

[0004]

However, in the above-mentioned conventional oil mist alarm device, the valve element 5 of the rotary valve 51 is used.
Since 3 is intermittently rotated via the Geneva gear mechanism, even if the number of crank chambers is 6 and the inlet ports of Nos. 7 to 9 are unnecessary, the valve element temporarily stops even at these inlet ports. Therefore, assuming that the time including feed and temporary stop is 4 seconds per port, 40 seconds for one rotation of the valve body, that is, the blind time becomes 40 seconds, and the ratio of mist detectable time in one crank chamber decreases. There is. In addition, since the tungsten lamp 56 is used for the photoelectric tube 55, the durability is poor, and the maximum light quantity cannot be obtained immediately when the power is turned on, and the output voltage of the photocell 57 becomes less than the alarm set value. Therefore, although the alarm output is blocked by the CR circuit, this CR circuit does not work at the momentary power failure, so that there is a possibility that a false alarm is issued. in addition,
Since the whole alarm system is driven by 100-230V AC power supply, it is not suitable for diesel engines of ships that need to secure power supply even during blackout. Furthermore, the photocell 57
Since the zero point adjustment is manually performed by the user in consideration of the combination characteristics of the lamp, the photocell, the amplifier, etc., there is a problem that the adjustment is difficult and troublesome.

Therefore, an object of the present invention is to reduce the blind time for mist detection by devising the means for driving the valve element of the rotary valve and the method for adjusting the zero point of the output of the light receiving element, thereby annoying the user. Another object of the present invention is to provide an oil mist alarm device that can accurately and quickly detect oil mist over a long period of time and issue an alarm.

[0006]

In order to achieve the above object, an oil mist alarm device according to a first aspect of the present invention is provided with a casing, and a predetermined number of inlet ports that can be connected to respective crank chambers of an engine are rotationally driven. A rotary valve that sequentially communicates with the outlet port of the casing through a passage in the valve body, a light source at one end, and a light receiving element at the other end,
In the rotary valve, the outlet port of the rotary valve is provided in the inlet hole, and a phototube having a blower connected to the exit hole is provided to detect the concentration of the oil mist in each crank chamber flowing in the phototube and issue an alarm. A step motor for rotationally driving the valve body, an origin sensor for detecting the origin of the rotation angle of the valve body, and a port setting switch for specifying an inlet port connected to the crank chamber among the predetermined number of inlet ports. In response to the detection signal from the origin sensor, the step motor is stopped for a certain period of time at each inlet port position specified by the port setting switch and is not stopped at another inlet port.
When the rotation control is started and the detection signal from the origin sensor is not within the predetermined time, a rotary valve failure alarm is issued, while the detection signal in the non-mist state of the light receiving element and the specific inlet port When the difference signal from the detection signal when the valve disc is stopped at a predetermined value or more, the step motor is stopped at that position, and a mist alarm is provided. To do.

An oil mist alarm device according to a second aspect of the present invention further comprises an electromagnetic on-off valve that communicates the outlet port of the rotary valve with the atmosphere, and the control section receives a detection signal from the origin sensor only a predetermined number of times. , Stop the step motor for a certain period of time, and open the solenoid on-off valve,
The zero point of the phototube is automatically adjusted by using the detection signal of the light receiving element at that time as the detection signal in the non-mist state. An oil mist alarm device according to a third aspect is the one according to the second aspect, wherein the light source of the photoelectric tube is a light emitting diode that is intermittently turned on, and the control unit is
When the difference signal becomes a predetermined value or more for a certain period of time, the step motor is stopped at that position and a mist alarm is issued, and the alarm device is operated a predetermined number of times regarding the detection signal of the origin sensor. It is set small at the beginning and set large after that. The oil mist alarm device according to a fourth aspect of the present invention is the device according to any one of the first to third aspects, in which a DC power source is supplied to the photoelectric tube, the step motor, the origin sensor, the control unit, and the electromagnetic switching valve.

[0008]

In the oil mist alarm device according to claim 1, a predetermined number of inlet ports provided in the casing of the rotary valve are connected to respective crank chambers of the engine, and an outlet port of the casing is connected to an inlet hole of the photoelectric tube. A blower is connected to the exit hole of the photoelectric tube. The operator specifies the inlet port connected to the crank chamber among the predetermined number of inlet ports by the port setting switch. When the valve body of the rotary valve reaches the origin of the rotation angle,
The origin sensor that detects this outputs a detection signal to the control unit, and the control unit that receives this signal starts the control of one rotation of the step motor that rotationally drives the valve body. That is, the control unit drives the step motor to rotate the valve body once so that the valve body stops at each inlet port position specified by the port setting switch for a certain period of time and does not stop at other inlet ports. . Therefore, while stopping at the specified inlet port for a certain period of time, the oil mist in the corresponding crank chamber flows through the passage in the valve body and the outlet port in the photoelectric tube by the blower, and the light source that passes through this oil mist The light receiving element that receives the light from outputs a smaller detection signal as the mist concentration is higher. On the other hand, at the other inlet ports, the valve element is fast-forwarded without stopping. With this fast feed, the blind time for mist detection can be shortened, and the ratio of the mist detectable time per crank chamber can be increased. The control unit obtains the difference between the detection signal of the light receiving element in the non-mist state and the detection signal of the mist, and when this difference signal exceeds a predetermined value, the step motor is stopped at that position and a mist alarm is issued. , Notify the operator of the mist abnormality and its crankcase number. Further, when the detection signal from the origin sensor is not within the predetermined time, the control unit issues a rotary valve failure alarm because the valve body is not rotating normally.

According to another aspect of the oil mist alarm device of the present invention, there is provided an electromagnetic opening / closing valve that connects the outlet port of the rotary valve to the atmosphere. Then, every time the control unit receives the detection signal from the origin sensor a predetermined number of times, that is, every time the valve body rotates a predetermined number of times, a slight decrease in the output signal of the light receiving element occurs due to contamination by the mist in the photoelectric tube. , The valve body is stopped at the origin of the rotation angle for a certain period of time via the step motor, and the solenoid opening / closing valve is opened. Then, fresh outside air flows into the phototube, and the light receiving element outputs a detection signal in the non-mist state. Therefore, the control section automatically adjusts the zero point of the phototube using the output signal as the detection signal in the non-mist state. That is, the necessity of the mist alarm is determined by whether the difference signal between the detection signal in the non-mist state and the mist detection signal is a predetermined value or more, so that the operator does not have to manually adjust the inside of the phototube. It is possible to accurately detect the mist concentration regardless of the cloudiness of the lens, etc., and issue an accurate mist alarm.

According to another aspect of the oil mist alarm device of the present invention, the light source of the photoelectric tube is a light emitting diode which is intermittently turned on.
The light emitting diode is more durable than the conventional tungsten lamp, and the maximum amount of light can be obtained when the power is turned on, so that the false alarm is reduced. Also, the control unit stops the step motor and issues a mist alarm only when the difference signal becomes a predetermined value or more for a certain period of time, so the high-density mist that does not disappear instantaneously is avoided from adverse effects such as noise. It is possible to reliably detect and issue a more accurate mist alarm. Further, the above-mentioned predetermined number of times regarding the zero adjustment of the output of the photocell is set to be small at the initial stage of operation of the alarm device in which the temperature change of the semiconductor element of the control unit is large, and set to be large after that when the characteristics of the semiconductor element are stable, It is possible to eliminate the mist detection error due to the change with time, and to issue a more accurate mist alarm.

In the oil mist alarm device according to a fourth aspect of the present invention, since the DC power is supplied to the photoelectric tube, the step motor, the origin sensor, the control unit and the electromagnetic opening / closing valve, unlike the conventional example in which the commercial AC power supply is used, the black The power supply can be secured even when it is out, which is suitable for a diesel engine of a ship.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 is a configuration diagram showing an example of an oil mist alarm device of the present invention. This alarm device integrates a solenoid valve with a rotary valve, and directly drives a valve body to rotate by a step motor having an origin sensor. The configuration is the same as that of the conventional example described in FIG. 4 except that a control unit and a port setting switch are provided, and the same members as those in FIG. Casing 5 of rotary valve 51
The 10 inlet ports P provided in 2 are connected to the internal passage 53
The valve element 53, which is sequentially connected to the outlet port 54 via a, is rotationally driven by the step motor 1. On the drive shaft of the step motor 1, the rod 2 is fixed in the radial direction in order to detect the state where the valve body 53 is located at the 0th inlet port, that is, the origin of the rotation angle of the valve body, and corresponds to the 0th inlet port. A photo sensor 3 as an origin sensor for detecting passage of the rod 2 is provided at the position. Further, at the bottom of the casing 52, an electromagnetic opening / closing valve 4 that is opened and connects the outlet port 54 to the atmosphere is provided. In addition, the 0th inlet port is
It is closed without being connected to the crankcase. Further, as the light source of the photoelectric tube 55, the light emitting diode 5 which is intermittently turned on is used instead of the conventional tungsten lamp. Here, the reason why the light emitting diode 5 is turned on intermittently is that the oil mist concentration is continuous, so that, for example, the light emitting diode 5 is turned on every 0.1 to 0.2 seconds for measurement. This is because there is no problem in practical use, and by doing so, there is an advantage that the life of the light emitting diode 5 can be further extended and that the current can be increased and the light can be emitted with high brightness as compared with the case of continuous illumination.

FIG. 2 is a block diagram showing a control system of the alarm device. The alarm device includes a CPU (microcomputer) 6 as a control unit for controlling each block, a port setting switch 7 for setting the number of inlet ports actually connected to the crank chamber at knob positions 1 to 9, and a step. A motor driver 8 for controlling the motor 1, a mist indicator 9 for displaying the detected mist concentration in a bar graph by flickering 16 light emitting diodes, and each output relay 1
It is equipped with alarm lamps 13, 14, 15 which are turned on by 0, 11, 12 and respectively indicate a device failure, a medium concentration mist (mist indicator level 11) and a high concentration mist (mist indicator level 16). 24V DC power is supplied through the fuse 16 and the power switch 17.
The detection signal from the photocell 57 of the photoelectric tube 55 is amplified by the IC amplifier 19 with the gain adjustment knob 18,
The digital signal is converted by the D converter 20 and input to the CPU 6. When the number of inlet ports to be connected to the crank chamber is set by the port setting switch 7, the first to the inlet ports corresponding to the set number are sequentially connected to each crank chamber in ascending order of chamber number. It

When the CPU 6 receives the detection signal from the photo sensor 3 for detecting the origin of the rotation angle of the valve body 53 (the position of the 0th inlet port), the CPU 6 operates from the 1st to the number corresponding to the set number of the port setting switch 7. Control of one rotation of the step motor 1 is started so that each inlet port position is stopped for a certain period of time and the other inlet ports are not stopped. Here, for each of the entrance ports specified by the port setting switch 7, the time including the feeding and the temporary stop is 1 second, and the other entrance ports that are fast-forwarded without stopping are required. Time is 0.
It takes about 2 seconds. If the detection signal from the photo sensor 3 is not input for a predetermined time (for example, 20 seconds), it is determined that the valve body 53 of the rotary valve 51 is not rotating normally, and the alarm lamp 13 for failure is output via the output relay 10. Is turned on and an alarm is issued.

Further, the CPU 6 controls the photocell 5 described later.
The difference between the detection signal (reference voltage) in the non-mist state obtained by the automatic zero adjustment of the output of 7 and the detection signal when the valve body 53 is stopped at the specified inlet port is calculated. Exceeds the first threshold value indicating the medium mist concentration for 0.5 seconds or more, the alarm lamp 14 for medium mist concentration is turned on via the output relay 11 to issue an alarm, and the difference signal is output for 0.5 seconds or more. If the second threshold value representing the high mist concentration is exceeded, the alarm lamp 15 for the high mist concentration is turned on via the output relay 12 to issue an alarm, and the step motor 1 is immediately passed through the motor driver 8 at that position. Stop. In FIG. 2, 21 is a test button for arbitrarily testing the operation of the alarm circuit, and 22 is a test button.
Is a reset button for returning the alarm device to the initial state when the alarm lamp 14 for high mist concentration is activated,
Reference numeral 23 is a blinking lamp that blinks in a normal state.

Further, since the CPU 6 causes a slight decrease in the photocell output due to contamination of the lens 61 due to mist, etc., the automatic zero adjustment is performed to eliminate the detection error due to this.
The procedure is as follows. That is, the CPU 6
Counts the detection signal from the photo sensor 3 emitted once for each rotation of the valve body 53, and at the beginning of the operation of the alarm device, each time the count value increases by 6, the valve is detected at the 0th port position. The body 53 is stopped, and the electromagnetic open / close valve 4 is excited for 4 seconds repeatedly 10 times. After that, the electromagnetic open / close valve 4 is excited for 4 seconds each time the count value increases by 50.
Atmosphere (fresh air) is caused to flow from the outlet port 54 into the photoelectric tube 55 by opening the electromagnetic opening / closing valve. Then, the detection signal of the photocell 57 when the fresh air is flown is used as the detection signal (reference voltage) in the non-mist state, and the difference signal between this reference voltage and the mist detection signal of each crank is the first and second signals. The zero point adjustment of the photocell output is automatically performed by determining whether or not an alarm is necessary depending on whether or not the threshold value is exceeded. Here, since the time interval for zero adjustment requires a maximum of 10 seconds for one rotation of the valve body,
The initial period of operation is approximately 1 minute, and the period of time after that is approximately 10 minutes. The reason for providing such a difference is that the temperature change of the semiconductor element included in the CPU or the like is large at the initial stage of operation and becomes small thereafter.

The operation of the oil mist alarm device having the above structure will be described below with reference to the flowchart of FIG. The operator determines the number of inlet ports connected to the crank chamber of the diesel engine among the first to ninth inlet ports P provided in the casing 52 of the rotary valve 51 (see FIG. 1) by the port setting switch 7 (see FIG. For example, 6 (corresponding to 6 crank chambers) is set by the knob (see 2). When the valve body 53 of the rotary valve reaches the 0th inlet port,
The photosensor 3 that detects this outputs a detection signal to the CPU 6, and the CPU 6 that has received this detection signal starts the processing of FIG. 3, which is the control of one rotation of the step motor 1, that is, the valve body 53.

That is, the CPU 6 executes step S1 in FIG.
Then, initialization is performed, and since it is already in the state of step S2,
In step S3, whether or not it is the zero adjustment time is determined by multiplying the count value of the detection signal from the photo sensor 3 by 6 (the count value is 6).
Whether it is 0 or less) or a multiple of 50 (count value is 6
(If it is 0 or more) When it is determined that it is the zero-point adjustment time, the process proceeds to steps S4 and S5, the electromagnetic on-off valve 4 is opened, and the 4-second timer starts counting. Then, fresh outside air flows into the photoelectric tube 55 through the outlet port 54 (see FIG. 1), and the photocell 57 outputs a detection signal in the non-mist state to the CPU 6. Therefore, CPU6
After the time of 4 seconds described above, the valve body 53 is located at the 0th inlet port, so it is determined to be affirmative in step S6, and step S6
At 7, the detection signal in the non-mist state is set as a reference voltage. Next, also in step S8, since the valve body is in the 0th port, it is determined to be affirmative, and the process proceeds to step S9.

The CPU 6 closes the electromagnetic on-off valve 4 in step S9, and in steps S10 and S11, rotates the step motor 1 to the first port by one port at the same time.
Starts the counting of the second timer. By the time it is determined in step S15 that the time measurement by the 1-second timer is completed, the valve body reaches port 1 in approximately 0.2 seconds, and the oil mist in the first crank chamber is stopped by the photoelectric tube during the 0.8 second pause. 55, the mist detection signal from the photocell 57 is read into the CPU 6 in step S12, and in step S13,
The difference between the reference voltage and the read detection signal is obtained, and in step S14, the mist indicator 9 is turned on to a level according to the difference signal. If it is determined in step S15 that one second has elapsed, the process returns to step S6.

At this time, since the valve body is at the 1st port,
In step S6, it is determined to be no, the process proceeds to step S16, it is determined whether or not the difference signal exceeds the first threshold value for 0.5 seconds or more, and if it is determined to be no, step S8,
After S9, in step S10, the valve body is further rotated by one port to the second port, and steps S12 and S13 are performed.
After that, in step S14, the mist concentration of the second crank chamber is displayed on the mist indicator 9. Thus, the sixth
Mist concentration up to the crank chamber is low (below the first threshold)
If the mist indicator 9 repeats the above path
The mist concentration of each crank chamber is displayed in a bar graph one after another, and when the valve body reaches the 7th port which is not connected to the crank chamber, it is determined as NO in step S8, and step S8 is performed.
Returning to step 2, the valve element is fast-forwarded to the 0th port in step S2 without stopping. Then, step S3
If it is determined that it is not the zero point adjustment time, the processing such as mist concentration display for the ports 1 to 6 after the above step S8 is performed, and if it is determined that the zero point adjustment time is reached, the steps S4 to S7 are performed. The zero point adjustment process is performed again. Although not shown in FIG. 3, the CPU 6
When the detection signal from the photo sensor 3 which is the origin sensor of the valve body is not within a predetermined time (for example, 20 seconds), the valve body 5
Assuming that 3 is not rotating normally, the alarm lamp 13 for failure is turned on via the output relay 10 to issue a rotary valve failure alarm.

As described above, the step motor 1 controlled by the CPU 6 rapidly feeds the valve body 53 to the inlet port not connected to the crank chamber, so that the time required for one rotation of the valve body is the same as that of the conventional Geneva gear mechanism. Driven by 4
The time can be significantly reduced from 0 seconds to a maximum of 10 seconds, the blind time for mist detection is shortened, and the probability of mist abnormality detection can be greatly improved. Also, the CPU 6
Thus, the electromagnetic on-off valve 4 is opened at a predetermined time interval based on the detection signal of the photo sensor 3 at the 0th port position of the valve body.
Since the output of the photocell 57 is automatically adjusted to the zero point, the operator's time and effort are saved, and the mist density is accurately detected regardless of the fog caused by the mist of the lens 61 of the photoelectric tube 55.
As described later, an accurate mist alarm can be issued. In addition, the above-mentioned predetermined time interval is set to be small in the initial stage of operation of the alarm device in which the temperature change of the semiconductor element such as the CPU 6 is large, and is large after the characteristic of the semiconductor element is stable. It is possible to eliminate the accompanying mist detection error. Further, the CPU 6 starts the control of one rotation of the valve body via the step motor 1 every time the detection signal of the photo sensor 3 is received, that is, every time the valve body 53 comes to the 0th port, and the step motor 1 emits. If the number of pulses matches the preset number of pulses depending on the port position, it is judged that the valve body has reached that port.Therefore, even if the stop position at each inlet port of the valve body shifts, that position shift Is corrected for each rotation, the valve element can be accurately driven in combination with the warning of the rotary valve failure described above.

Next, at step S16 of FIG. 3, when it is judged that the difference signal between the reference voltage and the mist detection signal of each crank chamber exceeds the first threshold value for 0.5 seconds or more, the routine proceeds to step 17. The photocell voltage, that is, the mist signal is read by the CPU 6, the difference signal is obtained in step S18, and the mist concentration corresponding to the difference signal is displayed in a bar graph on the mist indicator 9 in step S19, and the output relay The alarm lamp 14 for medium mist concentration is turned on via 11 to issue an alarm. If the difference signal does not exceed the second threshold value for 0.5 seconds or more, it is determined as NO in step S20, and the process returns to step S8, while the difference signal exceeds the second threshold value for 0.5 seconds or more. Proceeds to step S21. Step S21
Then, similarly to the above, the mist concentration corresponding to the difference signal is displayed in a bar graph on the mist indicator 9, and the alarm lamp 15 for high mist concentration is turned on via the output relay 12 to give an alarm and the step motor 1
The valve body 53 is immediately stopped via the. Therefore,
The operator can know the crank chamber number of the mist abnormality of high mist concentration from the stop position of the valve element. Finally, in step S22, the reset button 22 (see FIG. 2)
It is determined whether or not is pressed, and if it is determined that it is pressed, the process proceeds to step S23, the alarm lamps 15 and 14 are turned off via the output relays 12 and 11, and the CP
After initialization by U6, the process returns to step S2.

In the above embodiment, the light source of the phototube 55 uses the light emitting diode 5 which is intermittently turned on, and is superior in durability as compared with the conventional tungsten lamp, and the maximum amount of light can be obtained when the power is turned on. The number of false alarms is reduced. In addition, when the difference signal exceeds the first and second threshold values for a certain period of time, respectively, a mist alarm and a high mist concentration alarm (two-stage alarm) are issued. There is an advantage that the high-concentration mist can be reliably detected without adverse effects such as noise, and a more accurate and detailed mist alarm can be issued. Further, in the above embodiment, as can be seen from FIG. 2, the photoelectric tube 55, the step motor 1, the photo sensor 3,
Since 24V DC power is supplied to the CPU 6 and the electromagnetic opening / closing valve 4, unlike the conventional example in which an AC power supply of 100 to 230V is used, the power supply can be secured even during blackout, and it is suitable for a diesel engine of a ship. . Further, since the control system including the CPU 6 is formed as a printed circuit board and the valve body 53 is directly driven to rotate by the program control of the step motor 1 by the CPU 6, the valve body is driven to rotate intermittently via the AC motor and the Geneva gear mechanism. Compared with the conventional example, the alarm device can be simplified and made compact, the failure rate of the device is reduced,
The reliability of the device can be greatly improved.

[0024]

As is apparent from the above description, claim 1
The oil mist alarm device described in (1) sets a step motor that rotationally drives a valve element of a rotary valve that sequentially connects and switches a predetermined number of inlet ports that can be connected to each crank chamber of the engine to an outlet port, and a rotation angle origin of the valve element. The origin sensor to detect, the port setting switch to identify the inlet port connected to the crank chamber, and the step motor receives each detection signal from the origin sensor. Stops for a certain period of time and starts controlling one step of the step motor so that it does not stop at other inlet ports, and when the detection signal from the origin sensor is not within the predetermined time, a warning of rotary valve failure is given. Is emitted, the detection signal when the light receiving element is in the non-mist state and the detection when the valve body is stopped at the specific inlet port When the difference signal between the signal exceeds a predetermined value, it stops the step motor at that position,
In addition, since it has a control unit that issues a mist alarm, the time required for one rotation of the valve body can be greatly shortened compared with the drive by the conventional Geneva gear mechanism, and the blind time for mist detection is shortened. In addition to improving the probability of detecting a mist abnormality, the valve disc can be driven accurately by compensating for the stop position deviation with respect to the inlet port each time by controlling the valve disc per revolution, and it can also be stopped when a mist alarm is issued. The number of the crank chamber in which the mist is abnormal can be known from the position of the valve body.

An oil mist alarm device according to a second aspect of the present invention further comprises an electromagnetic on-off valve that communicates the outlet port of the rotary valve with the atmosphere, and the control section receives a detection signal from the origin sensor only a predetermined number of times. , The step motor is stopped for a certain period of time, and the electromagnetic opening / closing valve is opened.The detection signal of the light receiving element at that time is automatically detected as the detection signal in the non-mist state, and the zero point of the photoelectric tube is automatically adjusted. Therefore, it is possible to accurately detect the mist concentration and issue an accurate mist alarm regardless of the fogging caused by the mist of the lens of the photoelectric tube or the like, while saving the operator's trouble.

In the oil mist alarm device according to a third aspect of the present invention, the light source of the photoelectric tube is a light emitting diode that is intermittently turned on, and the control unit is such that when the difference signal becomes a predetermined value or more for a certain period of time. The step motor is stopped and the mist alarm is generated, and the predetermined number of times regarding the detection signal of the origin sensor is set to be small at the beginning of the operation of the alarm device and set to be large after that, so compared with the conventional tungsten lamp. It has excellent durability, maximum light intensity can be obtained at the same time when power is turned on, and false alarms are reduced, and high-density mist that does not disappear instantaneously can be reliably detected while avoiding adverse effects such as noise. An alarm can be issued. Further, by setting the predetermined number of times, it is possible to eliminate the mist detection error due to the change over time of the characteristic value of the semiconductor element, and to issue a more accurate mist alarm.

In the oil mist alarm device of the fourth aspect, since the DC power source is supplied to the photoelectric tube, the step motor, the origin sensor, the control section and the electromagnetic on-off valve, unlike the conventional example in which the commercial AC power source is used, the black The power supply can be secured even when it is out, which is suitable for a diesel engine of a ship.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an oil mist alarm device of the present invention.

FIG. 2 is a block diagram showing a control system of the above embodiment.

FIG. 3 is a flowchart showing a flow of operations of the above embodiment.

FIG. 4 is a configuration diagram showing a conventional oil mist alarm device.

[Explanation of symbols]

1 ... Step motor, 2 ... Rod, 3 ... Photo sensor,
4 ... Electromagnetic on-off valve, 5 ... Light emitting diode, 6 ... CPU, 7
… Port setting switch, 9… Mist indicator, 13
... alarm lamp for failure, 14 ... alarm lamp for medium mist concentration, 15 ... alarm lamp for high mist concentration, 51 ... rotary valve, 52 ... casing, 53 ...
Valve body, 54 ... Outlet port, 55 ... Phototube, 55a ... Inlet hole, 55b ... Outlet hole, 57 ... Photocell, 58 ... Blower, 61 ... Lens, P ... Inlet port.

Claims (4)

(57) [Claims] 1. A rotary valve, which is provided in a casing and sequentially switches a predetermined number of inlet ports that can be connected to respective crank chambers of an engine to an outlet port of the casing through a passage in a valve body that is rotationally driven to communicate with the rotary valve. , A light source is provided at one end, a light receiving element is provided at the other end, an outlet port of the rotary valve is provided at an inlet hole, and a photoelectric tube to which a blower is connected is provided at the outlet hole. In the oil mist alarm device that detects the concentration of the above and issues an alarm, a step motor that rotationally drives the valve element of the rotary valve, an origin sensor that detects the origin of the rotation angle of the valve element, and the predetermined number of inlet ports Among them, the step setting switch for specifying the inlet port connected to the crank chamber and the detection signal from the origin sensor receive the step mode The controller stops at each inlet port position specified by the port setting switch for a certain period of time, and starts the control of one rotation of the step motor so that it does not stop at other inlet ports, and the detection signal from the origin sensor When it is not within a predetermined time, the warning of rotary valve failure is issued, while the difference signal between the detection signal in the non-mist state of the light receiving element and the detection signal when the valve disc is stopped at the specific inlet port. Is a predetermined value or more, the oil mist alarm device is provided with a control unit that stops the step motor at that position and issues a mist alarm. 2. The oil mist alarm device according to claim 1, further comprising an electromagnetic on-off valve that communicates an outlet port of the rotary valve with the atmosphere, and the control unit outputs a detection signal from the origin sensor a predetermined number of times. Each time it is received, the step motor is stopped for a certain period of time, and the solenoid on-off valve is opened, and the detection signal of the light receiving element at that time is automatically adjusted as the detection signal in the non-mist state to adjust the zero point of the photoelectric tube. An oil mist alarm device that is designed to operate. 3. The light source of the photoelectric tube is a light emitting diode that is intermittently turned on, and the control unit controls the position of the step motor when the difference signal exceeds a predetermined value for a certain period of time. The oil mist alarm device according to claim 2, wherein the oil mist alarm device is set to be small at the beginning of the operation of the alarm device and set to be large thereafter after the predetermined number of times regarding the detection signal of the origin sensor is stopped while the mist alarm is issued. 4. The oil mist alarm device according to claim 1, wherein a direct current power is supplied to the photoelectric tube, the step motor, the origin sensor, the controller and the electromagnetic on-off valve.