JP4236066B2 - Rust prevention device for fuel injection system parts in marine engines - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of rust prevention devices for fuel injection system parts in marine engines.
[0002]
[Background Art and Problems to be Solved by the Invention]
In a marine engine such as an outboard motor, it is inevitable that seawater is mixed into the fuel tank due to fuel replenishment at sea due to the usage environment. In this case, marine engines that use fuel injection systems usually use iron-based parts such as electric pumps, injectors, and regulators, so if seawater enters the fuel, rusting, etc. The effect on the inside of the parts becomes a problem. In particular, regarding the electric pump for supplying fuel, it also serves as cooling of the inside of the main body, and the fuel is allowed to flow directly around the armature, brush, etc. When seawater is mixed in the fuel,
(1) Parts such as motor bearings corrode, causing abnormal noise and vibration from the pump, and friction increases due to bearing backlash, resulting in increased current consumption.
(2) Since seawater has electrical conductivity, a local short circuit occurs in the brush part, and the progress of brush wear is accelerated.
(3) Electrolysis of water occurs at the brush part, and the metal cation and hydroxyl group in seawater react with each other to generate salt (hydroxide), that is, foreign matter is generated in the fuel and pressure loss is increased. Such problems arise.
[0003]
For this reason, there is a conventional example of premixing all the oil for engine lubrication in the outboard motor or one port of the oil pump for engine lubrication in the fuel, but only for rust prevention inside the parts. If so, there is no need to mix a large amount of oil, as in the case of a direct injection engine, when oil for engine lubrication cannot be premixed in the fuel, or when excessive oil is premixed, white smoke, deterioration of oil consumption, There is a problem that plug fouling occurs.
[0004]
The present invention solves the above-mentioned conventional problems, and even when seawater is mixed in the fuel, the required amount of oil is always premixed in the fuel, thereby preventing rust prevention inside the fuel injection system components. An object of the present invention is to provide a rust preventive device for fuel injection system parts in a marine engine capable of preventing generation of white smoke, deterioration of oil consumption, and plug fouling while maintaining.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, in the fuel-injected marine engine, an electric oil pump for fuel premix is provided separately from the oil pump for engine lubrication to lubricate the engine. A part of the oil is premixed with the fuel, and a predetermined amount of oil is premixed except for the engine low load and the low engine speed range where white smoke is generated and the effect of the plug foul is produced. The invention is characterized in that, in claim 1, the engine is an in-cylinder fuel injection engine, and oil is premixed in a fuel separator tank or a fuel pipe starting from or ending at the vapor separator tank. According to the invention described in claims 1 and 2, the oil is primed so that the mixing ratio of the oil to the fuel is constant. According to a fourth aspect of the present invention, in the first to third aspects of the present invention, a water detection sensor for detecting water in the fuel is provided, and oil is preliminarily detected when mixing of water in the fuel is detected. The invention according to claim 5 is characterized in that when the oil temperature is low, the oil premix amount is corrected to be increased.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of an outboard motor showing an embodiment of the present invention, where FIG. 1 (A) is a plan view of the engine, and FIG. 1 (B) is a longitudinal sectional view taken along line BB in FIG. 1 (A). (C) is a side view of the outboard motor, and (D) is a configuration diagram of the fuel supply system.
[0007]
Reference numeral 1 denotes an outboard motor. An engine 2 on which the crankshaft 10 is mounted in a vertical state, a guide exhaust portion 3 connected to the lower end surface of the engine 2 and supporting the engine 2, and a lower end surface of the guide exhaust portion 3 The upper case 4, the lower case 5, and the propeller 6 are connected. The engine 2 is an in-cylinder injection type V-type six-cylinder two-cycle engine, and the six cylinders 7a to 7f are arranged horizontally in two rows so as to form a V bank in plan view. A cylinder head 8 is connected and fixed to the cylinder body 7.
[0008]
Pistons 11 are slidably fitted in the cylinders 7 a to 7 f, and each piston 11 is connected to the crankshaft 10. The cylinder head 8 is equipped with a solenoid opening / closing type fuel injection valve 13 and a spark plug 14 that are opened and closed by magnetic force. The cylinders 7a to 7f communicate with the crank chamber 12 through scavenging ports (not shown), and an exhaust port 15 is connected to the cylinders 7a to 7f. The exhaust port 15 in the left bank in FIG. 1B is joined to the left collective exhaust passage 16, and the exhaust port 15 in the right bank is joined to the right collective exhaust passage 17. An intake passage 19 branched from the intake manifold is connected to the crank chamber 12 of the engine 2, and a reed valve 20 for preventing backflow is disposed at a connection portion of the intake passage 19 to the crank chamber 12. Further, an oil pump 21 for supplying and lubricating oil into the engine and a throttle valve 22 for adjusting the intake air amount are disposed on the upstream side of the reed valve 20.
[0009]
As shown in FIG. 1 (D), the fuel in the fuel tank 23 installed on the hull side is passed through a fuel filter 26 by a manual first low-pressure fuel pump 25 and a second low-pressure on the outboard motor side. It is sent to the fuel pump 27. The second low-pressure fuel pump 27 is a diaphragm pump that is driven by the pulse pressure of the crank chamber 12 of the engine 2 and sends fuel to a vapor separator tank 29 that is a fuel tank having a gas-liquid separation function. A fuel preload pump 30 driven by an electric motor is disposed in the vapor separator tank 29, and the fuel is pressurized and sent to the high pressure fuel pump 32 through the preload pipe 31. The discharge side of the high-pressure fuel pump 32 is connected to a fuel supply rail 33 arranged in the vertical direction along each cylinder 7 a to 7 f, and is connected via a high-pressure control valve 35, a fuel cooler 36, and a return pipe 37. Are connected to the vapor separator tank 29. A preload pressure adjustment valve 39 is provided between the preload pipe 31 and the vapor separator tank 29. The high pressure fuel pump 32 is driven by a pump drive unit 40. The pump drive unit 40 is connected to the crankshaft 10 via a belt 41.
[0010]
The oil pump 21 for engine lubrication is a pump driven by the rotation of the crankshaft 10, and oil is supplied into the intake passage 19 from a sub tank 50 installed on the hull side through a main tank 51 arranged on the engine side. Supply. The oil pump 21 may be electrically operated. The oil in the main tank 51 is configured to be supplied to the vapor separator tank 29 via the filter 52, the fuel premix oil pump 53, and the check valve 54. The fuel premix oil may be supplied to the high-pressure fuel return pipe 37 or may be supplied to the discharge side of the second low-pressure fuel pump 27.
[0011]
The ECU (electronic control unit) 42 receives detection signals from various sensors indicating the driving state of the engine 2, the outboard motor 1 and the state of the ship. For example, an engine rotation speed sensor 43 that detects the rotation angle (rotation speed) of the crankshaft 10, an intake air temperature sensor 44 that detects the temperature in the intake passage 19, a throttle opening sensor 45 that detects the opening of the throttle valve 22, An air-fuel ratio sensor 46 for detecting the air-fuel ratio in the uppermost cylinder 7d, a fuel pressure sensor 47 for detecting the pressure in the high-pressure fuel pipe, a cooling water temperature sensor 48 for detecting the cooling water temperature of the engine, and water in the fuel filter 26 A signal from the detection sensor 55 and the like is input. The ECU 42 performs arithmetic processing on the detection signals of these sensors based on the control map, and transmits the control signals to the fuel injection valve 13, the spark plug 14, the preload fuel pump 30, and the fuel premix oil pump 53.
[0012]
The fuel premix oil pump 53 employs a pump driven by an electromagnetic solenoid or a pump driven by an electric motor. 2 shows a fuel premix oil pump of the type driven by an electric motor, FIG. 2 (A) is a front view, FIG. 2 (B) is a view seen from the B direction of FIG. 2 (A), FIG. (C) is sectional drawing cut | disconnected by CC line of FIG. 2 (B), and looked at the arrow direction. In the figure, 53a is a motor input shaft, 53b is a worm gear, 53c is a rotating shaft meshing with the worm gear 53b, 53d is a plunger, 53e is a cam, 53f is a sub-plunger, 53g is a spring, 53h is a suction pipe, and 53i is a discharge pipe. .
[0013]
FIG. 3 is a cross-sectional view showing the configuration of the vapor separator tank 29. The vapor separator tank 29 includes a case body 29a, a lid body 29b fixed to the case body 29a, a filter 56 and a preload fuel pump 30 disposed in the case body 29a, and a pump terminal attached to the lid body 29b. 57, a preload pressure adjusting valve 39, a fuel inlet 29c and an oil inlet 29d formed in the lid 29b, and a float valve 29e attached to the lower part of the fuel inlet 29c. The preload fuel pump 30 has a pump impeller portion 30a, a coil portion 30b, and a brush portion 30c. Further, the oil inlet portion 29 d is communicated with the fuel return passage 29 f of the preload pressure adjusting valve 39. Reference numeral 29g denotes an engine mounting bracket.
[0014]
FIG. 4 is a cross-sectional view showing the configuration of the fuel filter 26 of FIG. The fuel filter 26 includes a filter case 26a, a lid 26c that is detachably attached to the filter case 26a by a screw member 26b, a fuel inlet pipe 26d, a fuel outlet pipe 26e, and a filter locking member provided on the lid 26c. 26f, and a filter material 26g is attached to the filter locking member 26f. A protruding portion 26h is formed on the bottom surface of the filter case 26a, and a cylindrical member 26i is screwed into the protruding portion 26h, and the filter locking member 26f is supported by the upper end of the cylindrical member 26i. A resin float member 26j is slidably fitted to the outer periphery of the cylindrical member 26i, and a spring 26k is disposed between the inner stepped portion of the filter case 26a and the filter locking member 26f. Further, a magnetic proximity switch 26m is disposed inside the cylindrical member 26i, and the proximity switch 26m is connected to the external wiring 26n. A water detection sensor 55 is constituted by the float member 26j and the proximity switch 26m.
[0015]
As shown by the arrows in the figure, the fuel flows into the filter case 26a from the fuel inlet pipe 26d, and the lighter specific gravity of the fuel is removed while passing through the filter material 26g. The fuel is directed to the fuel outlet pipe 26e and into the fuel. The mixed water with a high specific gravity is stored in the filter case 26a. At this time, the flow rate of the fuel flowing in by the spring 26k is weakened to prevent the water accumulated in the lower portion of the filter case 26a from being stirred. As the water accumulates in the filter case 26a, the float member 26j moves upward. When the proximity switch 26m detects this, an alarm lamp or the like warns. And a user loosens screw member 26b, removes filter case 26a, and removes water inside.
[0016]
The operation of the present invention having the above configuration will be described. The fuel in the vapor separator tank 29 is preloaded by the fuel preload pump 30 to about 3 to 10 kg / cm ² , and the pressurized fuel is added to about 50 to 100 kg / cm ² by the high pressure fuel pump 32 or more. In the pressurized and pressurized high pressure fuel, surplus fuel exceeding the set pressure is returned to the vapor separator tank 29 by the pressure regulating valve 35, and only the necessary high pressure fuel is supplied to the fuel supply rail 33, and each cylinder 7a. ˜7f is supplied to the fuel injection valve 13. The oil pump 21 is driven by the rotation of the crankshaft 10 and supplies oil from the sub tank 50 and the main tank 51 into the intake passage 19 to lubricate the inside of the engine. Further, the fuel premix oil pump 53 is driven to supply oil in the main tank 51 to the vapor separator tank 29 via the filter 52 and the check valve 54. For this reason, even if seawater is mixed in the fuel when the oil is premixed in the fuel and the fuel flows through the preload fuel pump 30, the preload pressure adjusting valve 39, and the fuel injection valve 13, the fuel injection system components are used by the oil. Rust prevention can be achieved.
[0017]
Here, the oil for fuel premix is intended to prevent rusting inside the parts, so there is no need to mix a large amount of oil, and excessive premixing of oil will cause white smoke, deterioration of oil consumption, plug A foul is generated. Therefore, in the present invention, the control is performed so that the oil premix amount is optimized. This will be described with reference to FIG.
[0018]
The control example of FIG. 5 (A) is a method of controlling the oil mixture ratio into the fuel to be constant. When the injection amount map Fnm is determined by the engine load and the engine speed, the oil premix amount is Fnm × C (C: constant). In the control example of FIG. 5 (B), the oil premix amount in the low load, low rotation speed range where the influence of white smoke generation and plug fouling appears is 0, and the oil premix amount in other operating ranges is A (fixed) Value). The control example of FIG. 5C is a method of increasing the oil premix amount for viscosity correction when the oil temperature (replaceable with the intake air temperature and the engine temperature) is low. Further, when water mixing is detected by the water detection sensor 55 described with reference to FIG. 4, control may be performed so as to supply or increase the premix oil.
[0019]
As shown in FIG. 6, when the fuel premix oil pump 53 is an electromagnetic pump, the number of energizations to the solenoid is reduced from the state (A) as shown in (B). This is performed by a method for controlling the frequency and a method for changing the frequency as shown in (C).
[0020]
Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications are possible. For example, in the above embodiment, the oil pump 53 for fuel premix is adopted, but without using this, the oil is branched from the discharge side of the oil pump 21 for engine lubrication, and this is used as the solenoid valve. Alternatively, it may be supplied to the fuel system.
[0021]
Moreover, in the said embodiment, although the example applied to the outboard motor is demonstrated, you may apply to the marine engine which installs an engine in the hull side. Moreover, although the said embodiment demonstrated the example applied to the in-cylinder injection type 2 cycle engine, it is applicable also to an intake injection type, and can also be applied to a 4 cycle engine.
[0022]
【The invention's effect】
As is apparent from the above description, according to the first to third aspects of the invention, even when seawater is mixed in the fuel, the oil is premixed in the fuel, thereby preventing rust inside the fuel injection system components. Can
According to the inventions of claims 4 to 7, the required amount of oil can be always supplied while maintaining the rust prevention inside the fuel injection system parts, and white smoke generation, deterioration of oil consumption, and plug fouling are prevented. can do.
[Brief description of the drawings]
FIG. 1 is a schematic view of an outboard motor showing an embodiment of the present invention, in which FIG. 1 (A) is a plan view of the engine, and FIG. 1 (B) is a longitudinal section taken along line BB of FIG. FIG. 2C is a side view of the outboard motor, and FIG. 2D is a configuration diagram of the fuel supply system.
2 shows an example of an oil pump for fuel premix in FIG. 1, FIG. 2 (A) is a front view, FIG. 2 (B) is a view seen from direction B in FIG. 2 (A), FIG. ) Is a cross-sectional view taken along the line CC of FIG. 2B and viewed in the direction of the arrow.
3 is a cross-sectional view showing a configuration of the vapor separator tank of FIG. 1. FIG.
4 is a cross-sectional view showing the configuration of the fuel filter of FIG. 1. FIG.
FIG. 5 is a diagram for explaining control of an oil premix amount according to the present invention.
FIG. 6 is a diagram for explaining control of a premix oil pump according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 13 ... Fuel injection valve 21 ... Engine lubrication oil pump 29 ... Vapor separator tank 30 ... Preload fuel pump 32 ... High pressure fuel pump 53 ... Fuel premix oil pump 55 ... Water detection sensor

Claims (5)

In a fuel-injected marine engine, an electric oil pump for fuel premix is installed separately from the oil pump for engine lubrication, and a part of the oil for lubricating the engine is premixed with the fuel to generate white smoke. A rust preventive device for fuel injection system parts in a marine engine, wherein a predetermined amount of oil is premixed except for a low engine load and a low engine speed range affected by a plug foul . 2. The fuel injection system in a marine engine according to claim 1, wherein the engine is an in-cylinder fuel injection type engine and oil is premixed in a vapor separator tank or a fuel pipe starting from or ending at the vapor separator tank. Rust prevention device for parts. The rust preventive device for fuel injection system parts in a marine engine according to claim 1 or 2, wherein the oil is premixed so that the mixing ratio of oil to fuel is constant. 4. A fuel in a marine engine according to claim 1, wherein a water detection sensor for detecting water in the fuel is provided, and oil is premixed when mixing of water in the fuel is detected. Rust prevention device for jet system parts. The rust preventive device for fuel injection system parts in a marine engine according to any one of claims 1 to 4, wherein the oil premix amount is corrected to increase when the oil temperature is low.

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