KR20160007912A - System for Control Fuel Pump Plunger and Exhaust Valve in Ship - Google Patents

Abstract

The present invention relates to a system for remotely monitoring and controlling an exhaust valve mounted on an exhaust valve of a marine engine to confirm whether or not an exhaust valve is opened or closed as a result of combustion of an engine. An inductive sensor for sensing a current flowing through the sensor; A joint box connected to the plurality of inductive sensors by electric wires to process a signal sensed by the inductive sensor, and a fuel pump operation result of the hydraulic cylinder unit of the engine as feedback signals of the inductive sensor received in the joint box, And a remote monitoring system for engine control for determining and monitoring whether fuel is injected. It is considered that the present invention can be utilized for various purposes. The fuel pump plunger and the exhaust valve control system of a marine engine are capable of being applied to other fields as well as the fields of signal processing and stabilization of sensor signals in addition to cost reduction, performance improvement and stabilization.

Description

Technical Field [0001] The present invention relates to a fuel pump plunger and an exhaust valve control system for a ship,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for controlling a fuel pump plunger and an exhaust valve in a ship, and more particularly to a system for controlling a fuel pump plunger and an exhaust valve ≪ / RTI >

Inductive sensors, which are the core technology of fuel pump plungers and exhaust valve control systems, have been developed overseas. Fuel pump plunger and exhaust valve control systems have been increasingly applied to electronic engines since 2002, and efforts are being made to standardize the technology with competition for market preemption.

The most important technical factors in the fuel pump plunger and exhaust valve control system are increasing durability of inductive sensors and standardization of network. In particular, the standardization of the network supports the MODBUS protocol which seeks for the communication stability and interface convenience of marine electrical products. Inductive sensors of the fuel pump plunger and exhaust valve control system are integrated with the ship's control alarm system so that the standard protocol must be fully implemented so that collision with other systems in the network does not occur. MODBUS RTU (Remote Terminal Unit) of MODICON is provided as a standard in most of the currently commercialized electrical products. However, since it is necessary to establish the technology and countermeasures that can cope flexibly according to the protocol of the control alarm system, researches in these fields are actively conducted.

In Korea, Samsung Heavy Industries, Daewoo Shipbuilding & Marine Engineering, Hyundai Heavy Industries, and STX Heavy Industries, which are the four major shipyards, are now dependent on imports. It is the world's largest shipbuilding powerhouse in Korea, the world's largest shipbuilding power station. However, it is dependent on importing all of its raw materials in order to develop advanced technologies such as marine engine electronic control system and core surveillance / diagnosis system. And develop a proprietary model.

As a prior art related to the present invention, Patent Document 1 discloses a laser sensor 110 for measuring a distance between a target T and an inductive displacement sensor 400, a motor 130 for moving the target T, , And a motor controller (120) for controlling the motor (130) according to a control signal to vary a distance between the target (T) and the inductive displacement sensor (400). A temperature chamber (200) for setting the temperature of the inductive displacement sensor (400) according to a control signal; And outputs a control signal to the correction device 100 to control the distance between the target T measured by the laser sensor 110 and the inductive displacement sensor 400 and the output value of the inductive displacement sensor 400 A user terminal 300 for generating output value correction data of the inductive displacement sensor 400 required to indicate a linear output value according to a distance from the target T; And the output value of the inductive displacement sensor 400 is transmitted to the user terminal 300 and the output value correction data is received from the user terminal 300 and stored from the stored output value correction data to the inductive displacement sensor 400 And a sensor module (500) for correcting the output value of the inductive displacement sensor.

In Patent Document 2, when the position of the moving body changes, the impedance of the coil changes, and when the impedance of the coil changes, the voltage applied to the coil changes, and the position of the moving body is calculated from the change of the voltage. A method for measuring the position of a moving body using an impedance of a coil and an inductive position transmitter for implementing the method are disclosed.

In Patent Document 3, a cylinder rod 9 to be fixed to the cylinder portion 1 is provided inside the piston portion 4, and a cavity is formed in the cylinder rod 9 to insert the coil, The cylinder including the cylinder portion 1 and the piston portion 4,5 reciprocally movable to the cylinder portion 1 by detecting the position of the piston portion by varying the impedance according to the movement of the piston portion 4, .

In Patent Document 4, the hydraulic cylinder 1 includes a cylinder housing 3, a piston rod 7 that is reciprocally movable to the cylinder housing 3, a through hole 7a of the piston rod 7, Wherein the position detector (20) outputs an electric signal corresponding to the movement of the piston (6) and calculates the position of the piston (6) based on the electric signal The piston position sensing device of the hydraulic cylinder 1 is disclosed.

Patent Document 5 discloses that the four coils 3a-3d arranged around the magnetized object 1 are induced in voltage proportional to the velocity of the object 1 and the moving of the object 1 from the induced voltage Discloses a coil system for calculating the kinetic velocity of a magnetized object by calculating a velocity.

Patent Literature 6 discloses an inductive measuring apparatus comprising a sleeve tube 1, a core 2 provided inside the sleeve tube 1, and a coil 3 wound around the core 2, The inductive measurement device measures the impedance of the measurement device as the measurement object approaches and separates from the coil 3, and calculates the distance between the inductive measurement device and the measurement object from the variable impedance. An inductive measuring device for measuring a cylinder state of an internal combustion engine, that is, a wear of a cylinder liner, a piston, a piston ring, and the like is disclosed.

Korean Registered Patent No. 10-1049669 (issued on July 14, 2011) Danish patent publication DK151409 (published on July 26, 1986) Danish Published Patent Docket DK170624 (published Aug. 15, 1993) Danish patent publication DK165562 (published on August 21, 1988) Danish patent publication DK166050 (published on Mar. 27, 1985) Danish Patent Publication No. DK146422 (published on Mar. 26, 1977)

The present invention solves the above-mentioned problems, and it is an object of the present invention to provide a system and a method for operating a fuel injection valve, which is mounted on an exhaust valve of a marine engine and confirms whether an exhaust valve is opened or closed as a result of combustion of an engine, It is an object to provide a system for remote monitoring and control.

It is another object of the present invention to provide a system capable of remote monitoring including an inductive sensor capable of detecting a precise operation of an engine exhaust valve under severe conditions such as engine vibration and high temperature and high pressure, to be.

In order to achieve the above object, the present invention provides an inductive sensor for detecting whether an exhaust valve is open or closed, the inductive sensor being installed at one side of a plurality of exhaust valves of an engine; A joint box connected to the plurality of inductive sensors by electric wires to process a signal sensed by the inductive sensor, and a fuel pump operation result of the hydraulic cylinder unit of the engine as feedback signals of the inductive sensor received in the joint box, And a remote monitoring system for engine control for determining whether to inject fuel and monitoring the fuel pump plunger and the exhaust valve control system.

Further, in the present invention, a power supply for supplying power necessary for operation of the joint box and the remote monitoring system for engine control, and an uninterruptible power supply for supplying driving power when power is not supplied from the power supply And may further include a power supply (UPS).

According to another aspect of the present invention, there is provided an inductive sensor comprising: an oscillation unit mounted on the inductive sensor for sensing an eddy current generated in an exhaust valve positioned at a predetermined distance; and a control unit for generating a sinusoidal signal that varies in accordance with a change in distance between the inductor and the measured object A bias unit for rectifying and filtering the output of the oscillation unit to pass through the differential amplifier of OP-AMP to actively operate the amplitude of the oscillation unit signal to determine the operation reference point of the transistor from the signal detected by the detection unit, A filter unit for converting a ripple signal detected by the detection unit into a voltage signal for a distance, an amplifier for adjusting an offset of an output current by using a variable resistor in the signal input from the filter unit, And a voltage / current conversion unit for converting the input voltage signal into a current signal and outputting the current signal There.

Also, in the present invention, the oscillation portion includes an induction coil, and a distance of about 0.5 to 7.5 mm can be sensed according to the number of windings of the induction coil.

Further, in the present invention, the oscillation unit may include a sinusoidal oscillation circuit using LC resonance that amplifies a part of the energy stored in the resonance circuit and then supplies the amplified signal to the resonance circuit.

Further, in the present invention, the oscillation section may include a feedback circuit that feeds back a signal using a non-inverting amplifier of OP-AMP.

Further, in the present invention, the oscillation section may include a circuit for delaying a phase using an NPN transistor and a PNP transistor common emitter circuit.

Further, in the present invention, any one of a Hartley oscillator, a Colpitts oscillator, or a coherent oscillator may be used as the oscillation unit.

Further, in the present invention, the detecting section may include an on-wave rectifying circuit for outputting a voltage signal according to the distance.

Further, in the present invention, an RC filter circuit can be applied to the filter section.

Also, in the present invention, the voltage output from the voltage / current conversion unit may be about 1 to 5 V and the converted current may be about 4 to 20 mA.

Also, in the present invention, the inductive sensor may have a working range of about 150 to 200 ° C at a pressure of about 250 bar.

According to the present invention, in the technical aspect, first, a technology for transmitting real-time raw data using a sensor using a sensor processing algorithm is an essential source technology, and therefore, The technology can be transferred to the manufacturing industry and expanded to automation of aviation machines having dynamic mechanical systems other than ship engine. Second, improvement and standardization of commercialization technology by upgrading and expanding technology, Third, remote control and automation technology can be improved by the technology of world advanced countries so that real-time control can be performed using the network even in the remote place based on the world-class domestic IT-based technology. Fourth, as the development of real-time control structure, In the design field, which is difficult to relocate the technology, the design technique using mechanical kinetic analysis technique is secured by itself. Therefore, It can be applied to ship engine, aircraft and railway machine industry products by establishing a high quality engine design environment through transfer and securing technological competitiveness at the level of advanced companies at home and abroad. Sixth, it is dependent on major ship technology countries such as Norway and Germany. Through the development of system related technology, localization of automobile, aircraft and ship motion simulator can be sought. In addition, from the social and economic point of view, first, by developing automation equipment and supporting software for engine management, labor-oriented work can be replaced with an automation system, resulting in cost reduction through labor cost reduction, Second, productivity and economic efficiency are improved, and it is possible to acquire the productivity improvement and the cost reduction effect by making it possible to grasp the optimum work order through the effective equipment operation plan and perform the work accurately. Third, System is expected to be an important differentiating item of ship engine, it is expected to contribute greatly to domestic demand and export. Therefore, sales of ship engine sector is expected to expand. Fourth, remote control is required to isolate the operator of the equipment in harmful or dangerous work environment. To improve the safety of ship engine management. And (5) algorithm development through signal processing can be applied to industrial fields where automation is possible. (6) Real-time control structure development technology is superior to domestic companies that sell other exhaust valve control systems, And 7) real-time control structure development technology is the latest research field and it is a technology-intensive and venture-oriented type, so it provides independent research and development opportunities for related researchers, and 8) By securing the technology, it is possible to reduce the cost due to the transfer of the design technology of the advanced company. Ninthly, there is an advantage that the recognition of the product is enhanced by the high reliability through the self diagnosis of the failure.

1 is a configuration diagram showing a marine fuel pump plunger and an exhaust valve control system according to an embodiment of the present invention.
2 is a view showing an installation position of an inductive sensor in a marine engine according to the present invention.
3A and 3B are schematic views for explaining the operation principle of the inductive sensor in the present invention.
4 is a graphical representation of changes in amplitude and phase with respect to distance of an inductive sensor in the present invention.
5 is a graphical representation of the change in current with respect to distance of an inductive sensor in the present invention.
6 is a block diagram showing a circuit for processing a signal oscillated by an inductive sensor in the present invention.
7A and 7B show an oscillation circuit in the present invention as an example.
8 shows the detector circuit in the present invention as an example.
9 shows an example of the bias circuit in the present invention.
10 shows an example of the filter unit circuit in the present invention.
11 shows an amplifier section circuit in the present invention as an example.
12 shows an example of a voltage / current converter circuit in the present invention.
13 is a graph showing a current output value according to the number of windings of the head coil of the inductive sensor in the present invention.

Hereinafter, the fuel pump plunger and the exhaust valve control system according to the present invention will be described in detail with reference to the accompanying drawings.

1, the inductive sensor 10 is composed of a plurality of inductors. The inductive sensor 10 is mounted on one side of the exhaust valve of the marine engine. The inductive sensor 10 detects whether the exhaust valve is open or closed. That is, in Fig. 2, each inductive sensor 10 senses the opening and closing operation of each exhaust valve constituted on the engine.

A joint box (20) is connected to the plurality of inductive sensors (10) by electric wires to transmit and receive electrical signals. The joint box 20 processes signals sensed by each inductive sensor 10.

The remote monitoring system for engine control 30 determines whether fuel is injected or not by monitoring the fuel pump operation result of the hydraulic cylinder unit of the engine with the detection signal of the inductive sensor 10 received from the joint box 20 .

A power supply 50 for supplying power necessary for operation of the joint box 20 and the remote monitoring system 30 for engine control and a power supply connected in parallel with the power supply to supply the driving power when the power supply is not supplied with power An uninterruptible power supply (UPS) 40 is provided.

3A, the inductive sensor 10 generates an induced voltage on the metal conductor 1 in accordance with an electromagnetic induction action when the metal conductor 1 moves in a normal environment of a normal magnetic field or when a magnetic field passing through the conductor changes . The current that is distributed in a concentric circle around the magnetic flux by the voltage is called an eddy current.

When the magnetic flux B passes through the metal conductor 1, the eddy current flows on the circumference of the radius r around the point 0 where the metal surface and the magnetic flux B meet vertically.

At this time, the magnetic flux Φ penetrating perpendicularly to the conductor surface can be expressed as follows.

Therefore, the induced voltage from this flux

.

Since the eddy current generated by the induced voltage is distributed in the metal conductor 1, the total leakage current can be obtained by integration with respect to the radius r.

The total leakage current (i)

to be. Where Bm is the maximum value of the magnetic flux density, ω is the angular frequency (2ωπf), δ is the thickness of the metal conductor, and p is the volume specific resistance of the metal conductor.

If a metal conductor is present in the magnetic field generated by the coil, the entire magnetic flux is changed due to the eddy current generated in the metal conductor by the magnetic flux. The effect of this eddy current is used to measure the displacement or the thickness of the metal conductor. This is the operating principle of the inductive sensor.

3B, the inductive sensor 10 for high temperature and high voltage uses a high frequency magnetic field formed when passing a high frequency current generated in the head coil 3 . Eddy currents are generated on the surface of the target 2 in a direction perpendicular to the magnetic field by the electromagnetic induction phenomenon when the metal target 2 in the magnetic field is located. This results in a change in the impedance of the head coil 3. At this time, the inductive sensor 10 measures the distance between the targets 2 according to the change of the oscillation state.

4, when the target 2 approaches the head coil 3 of the inductive sensor 10, the amplitude becomes smaller and the phase difference becomes larger. By detecting a change in amplitude and a phase difference, the inductive sensor 10 can detect a value proportional to the change in distance from the target 2. [ That is, the inductive sensor 10, which can measure the gap between the metal conductor and the sensor in a noncontact manner by using the property that the inductance is changed by the air gap, constitutes an LC resonance circuit by using a coil and a capacitor, And the amount of passing magnetic flux changes depending on the distance between the metallic object and the metallic object. At this time, a voltage corresponding to the amount of change in the passing flux amount is generated across the coil. This generated voltage appears in a direction that interferes with the change in magnetic flux, and thus appears as a type of AC output. The AC signal is outputted through the constant current circuit and the current value corresponding to the distance.

The inductive sensor is a high frequency oscillation type. The high-frequency oscillation type uses a property that the magnetic flux generated through the high-frequency oscillation circuit changes when the metallic body approaches, and the oscillation state is changed and detected. A Hartley generator, a Colpitts oscillator, a tuned oscillator, and the like are mainly used for the circuit of the oscillation part to be mainly moved.

The inductive sensor of the present invention should be designed as a mechanical part and a circuit part. In the mechanical part, the environmental standard design conforming to the IP67 rating is applied as the design standard, and the required conditions are constant temperature and humidity, oil resistance, vibration and EMI / EMC. In the circuit part, it is designed by using a general high frequency oscillation type synchronous generator circuit and detects the change of the inductor time constant according to the distance change. In addition, it is necessary to improve the linearity of the inductive sensor by bias circuit improvement through trial and error to minimize discontinuous error between the value measured in the nonlinear manner and the ideal value.

5, when the inductive sensor 10 is fixed and the metal target 2 is moved, the distance L between the head coil 3 and the target 3 of the inductive sensor 10 is The current output from the output terminal of the inductive sensor 10 is approximately 4 to 20 mA. At this time, the output current has a substantially linearity depending on the distance between the head coil 3 and the target 2.

The inductive sensor 10 is preferably a high-performance inductive sensor with a precision of about 0.1 mm that can withstand the vibration and the harsh conditions due to the high temperature of the engine.

In addition, a non-linear method that minimizes discontinuous errors between measured values and ideal values can be applied.

6, the processing according to the detection by the inductive sensor 10 includes the inductance component L in the feedback element of the oscillation circuit, and the equivalent impedance due to the inductance is varied depending on the distance from the object to be measured, And the amplitude is converted into a voltage and then outputted as a current.

7, the oscillating unit 11 detects an eddy current generated in an exhaust valve of a marine engine mounted on the inductive sensor 10 and located at a certain distance. That is, in Fig. 7A, the basic oscillation circuit of the oscillation unit 11 is a sinusoidal oscillation circuit using LC resonance as the oscillation oscillator. This is a method of extracting a part of the energy stored in the resonance circuit, amplifying it, and supplying it to the resonance circuit, which has a frequency accuracy higher than that of the CR oscillation circuit. In FIG. 7B, a non-inverting amplifier of OP AMP is used as a feedback circuit to feedback the signal. NPN and PNP common emitter circuits can be used to implement a phase delay circuit.

8, the detection unit 12 generates a sinusoidal signal that changes in accordance with a change in the distance between the inductor and the measured object in the oscillation unit 11. [ That is, in Fig. 8, the detection unit 12 generates a sine wave signal whose amplitude varies according to the change in distance between the inductor and the measured object in the oscillation unit 11. Fig. It is preferable to output a voltage signal according to the distance using a full wave rectifier circuit.

9, the bias section 13 rectifies and filters the output of the oscillation section to determine the operation reference point of the transistor from the signal detected by the detection section 12, passes through the OP-AMP differential amplifier, Lt; RTI ID = 0.0 > a < / RTI > signal size. The bias voltage is a voltage applied to rectify and filter the output of the oscillation unit 11 and pass through the differential amplifier of the OP-AMP. The bias voltage Bias is applied to the oscillation unit 11 It is preferable to be actively operated with respect to the magnitude of the signal.

In Fig. 10, the filter unit uses an RC filter circuit to convert a ripple signal to a voltage signal for distance. That is, the cutoff frequency is approximately 1 KHz.

In FIG. 11, it is preferable that the amplifying unit 15 can adjust the offset of the output current by using a variable resistor in the signal input from the filter unit 14. [

12, the voltage / current (V-C) converter 16 converts the voltage signal inputted from the amplifier 15 into a current signal and outputs the current signal. The voltage / current conversion section 16 converts the voltage into a current using a voltage-current source circuit. It is preferable to apply an NPN transistor circuit for converting the voltage range of approximately 1 to 5 V to a current of approximately 4 to 20 mA and overcoming the current capacity of the current source OP amp.

On the other hand, in the inductive sensor 10, the head coil 3 for detecting the eddy current generated from the metallic derivative has a large variation in the linearity according to the number of turns of the induction coil, Since the linearity of the output current can not be secured in comparison with the distance to be determined, that is, approximately 0.5 to 7.5 mm, the winding factor of the coil can be regarded as an absolute proportion that determines the performance of the sensor. Therefore, through the winding test of the coil, the appropriate sensing coil is determined through the material selection, the winding bonding operation and the winding operation. For example, the sensing coil has a diameter of approximately 0.19 mm, a resistance value (at 20 ° C) of approximately 68,325 [Ohm / km], a polyamide self bonding wire bonding type, And the breakdown voltage (at 20 캜, 35% humidity) is preferably about 160 V / 탆.

Further, the calculation formula according to the number of coil turns is L (μH) = (d ² n ² ) / (18d + 40ℓ). Where L is the inductance (μH), d is the coil diameter (Inch, based on the wire center), l is the coil length (Inch), and n is the number of turns of the wire.

Therefore, when the actual number of turns is calculated, L = (0.0192 * 782) / (18 * 0.019 + 40 * 178.3).

In FIG. 13A, it is preferable that the number of turns of the coil is experimentally measured by the actual number of windings through the obtained coil to verify the variation of the number of turns with excellent linearity by checking the linearity period of the optimum number of turns. For the experiment, the same condition as the pumping time of the fuel pump was made, and the displacement change value was automatically changed from 0 to 7mm per 0.5mm, and the servo (Servo Motor, 220V, 12W) It is recommended to perform a functional test so that it can be displayed on a PC monitor. Therefore, in FIG. 13B, in the experiment, the linearity of the output relative to the distance is the best when the number of windings of the coil is 76.

In addition, vibration characteristics, temperature, and pressure of ships and engines vary depending on the ship 's Ahead and Astern operation and RPM. Therefore, the sensor per cylinder may show a large difference from the zero set at the time of non - operation. Therefore, by installing a sensor on a real ship, a look-up table for each operation situation is constructed and an automatic correction algorithm is implemented by applying an adaptive filter algorithm that can actively remove noise components according to driving conditions It is good to do. For this purpose, the automatic correction device, the automatic correction software, and the boot program of the unit are the same, but the application program must be programmed differently according to the function of each unit. In addition, digital signal processing and signal linearization techniques must be applied.

In addition, it is recommended to graphically display the signal-processed information from the sensor in real time for each cylinder so that the engine driver can easily control the exhaust valve by building a remote monitoring program. The user interface includes remote monitoring software for PCs that allows the operator to easily adjust settings, implement data in various ways as needed, and monitor and control in the engine control room. The remote monitoring software for PC includes a main window, a communication setting window, a packet extracting program, a communication debug window, and a script execution program.

While the invention has been shown and described with respect to the specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Anyone who has it will know it easily.

1: metal conductor 2: target 3: head coil 4: high frequency oscillation circuit 10: inductive sensor 11: oscillation section 12: detection section 13: bias section 14: filter section 15: amplification section 16: voltage / current conversion section 20: 30: remote monitoring system 40: uninterruptible power supply 50: power supply

Claims (12)

An inductive sensor installed on one side of a plurality of exhaust valves of the engine to detect whether the exhaust valve is open or closed;
A joint box connected to the plurality of inductive sensors by electric wires to process a signal sensed by the inductive sensor,
And a remote monitoring system for engine control for determining whether fuel is injected or not by feeding back the fuel pump operation result of the hydraulic cylinder unit of the engine with the detection signal of the inductive sensor received in the joint box, Valve control system.
The remote monitoring system for engine control according to claim 1, further comprising: a power supply for supplying power necessary for operation of said joint box and said remote control monitoring system for engine control; and an uninterruptible power supply connected in parallel with said power supply for supplying driving power when power is not supplied from said power supply Further comprising a device (UPS).
2. The exhaust gas purification apparatus according to claim 1, further comprising: an oscillation unit mounted on the inductive sensor and detecting an eddy current generated in an exhaust valve positioned at a predetermined distance;
A detector for generating a sinusoidal signal that varies in accordance with a change in distance between the inductor and the measured object in the oscillating unit;
A bias unit for rectifying and filtering the output of the oscillation unit to pass through the differential amplifier of OP-AMP to actively operate the amplitude of the oscillation unit signal to determine the operation reference point of the transistor from the signal detected by the detection unit,
A filter unit for converting the ripple signal detected by the detection unit into a voltage signal for distance,
An amplifier for adjusting an offset of an output current by using a variable resistor,
And a voltage / current converting unit converting the voltage signal input from the amplifying unit into a current signal and outputting the current signal.
4. The fuel pump plunger and exhaust valve control system according to claim 3, wherein the oscillation portion includes an induction coil and senses a distance of about 0.5 to 7.5 mm according to the number of windings of the induction coil.
4. The fuel pump plunger and exhaust valve control system according to claim 3, wherein the oscillation unit includes a sinusoidal oscillation circuit using LC resonance for amplifying a part of the energy stored in the resonance circuit and then supplying the amplified signal to the resonance circuit.
4. The fuel pump plunger and exhaust valve control system according to claim 3, wherein the oscillation portion includes a feedback circuit that uses a non-inverting amplifier of OP-AMP to feedback the signal.
4. The marine fuel pump plunger and exhaust valve control system according to claim 3, wherein the oscillation unit includes a circuit for delaying a phase using an NPN transistor and a PNP transistor common emitter circuit.
4. The fuel pump plunger and exhaust valve control system according to claim 3, wherein the oscillation unit is one of a Hartley oscillator, a Colpitts oscillator, or a synchronous oscillator.
4. The marine fuel pump plunger and exhaust valve control system according to claim 3, wherein the detecting section includes an on-wave rectifying circuit for outputting a voltage signal according to distance.
4. The marine fuel pump plunger and exhaust valve control system according to claim 3, wherein the filter portion is an RC filter circuit.
4. The fuel pump plunger and exhaust valve control system according to claim 3, wherein the voltage output from the voltage / current converter is about 1 to 5 V and the converted current is about 4 to 20 mA.
The fuel pump plunger and exhaust valve control system according to claim 1, wherein the operating range of the inductive sensor is about 150 to 200 ° C at a pressure of about 250 bar.

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