JP2004052627A - Fuel injection device and diesel engine equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device with a valve mechanism replaceable without stopping the operation of an engine, and a diesel engine equipped therewith. <P>SOLUTION: The fuel injection device 10 comprises a first accumulator 11 and a second accumulator 12 for storing a pressure rising fuel, a fuel injection valve 15 to be opened with fuel supply from theses accumulators 11, 12 for injecting the fuel, a fuel supply passage 16 for supplying the fuel from the first accumulator 11 and the second accumulator 12 to the fuel injection valve 15, a first valve mechanism 13 connected to the fuel supply passage 16 for on/off operation of the fuel supply from the first accumulator 11 to the fuel injection valve 15, and a second valve mechanism 14 connected to the fuel supply passage 16 for on/off operation of the fuel supply from the second accumulator 12 to the fuel injection valve 15. Flow fuses 24, 25 having over-outflow safety mechanisms are provided between the first accumulator 11 and the second valve mechanism 13 and between the second accumulator 12 and the second valve mechanism 14, respectively. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel injection device and a diesel engine having the same.
[0002]
[Prior art]
Recently, a pressure accumulator that stores pressurized fuel, a fuel injection valve that opens and injects fuel by supplying fuel from the pressure accumulator, and a fuel supply that supplies fuel from the pressure accumulator to the fuel injection valve There has been proposed a fuel injection device including a passage and a valve mechanism connected to the fuel supply passage to intermittently supply fuel to the fuel injection valve.
[0003]
[Problems to be solved by the invention]
However, in such a fuel injection device, when the valve mechanism malfunctions due to a failure or the like, it is necessary to temporarily stop the engine and then replace the valve mechanism. However, there is a problem in that during the exchange operation, the power cannot be temporarily secured, or in the case of a marine engine, the navigation becomes temporarily impossible.
[0004]
The present invention has been made in view of the above circumstances, and has as its object to provide a fuel injection device capable of replacing a valve mechanism without stopping the operation of the engine, and a diesel engine including the same.
[0005]
[Means for Solving the Problems]
The fuel injection device of the present invention and the diesel engine provided with the same employ the following means in order to solve the above problems.
That is, according to the fuel injection device of the first aspect, an accumulator that stores the boosted fuel, and a fuel injection valve that opens and injects the fuel when the fuel is supplied from the accumulator. A fuel supply path for supplying fuel from the pressure accumulator to the fuel injection valve, and a valve mechanism connected to the fuel supply path to intermittently supply fuel to the fuel injection valve, A flow fuse having an overflow safety mechanism is provided between the pressure accumulator and the valve mechanism.
[0006]
In this fuel injection device, a flow fuse having an overflow safety mechanism that shuts off the passage of fuel when the fuel passing therethrough exceeds a certain flow rate (the pressure difference between the upstream side and the downstream side exceeds a predetermined value) is used. , Provided between the pressure accumulator and the valve mechanism.
Therefore, even if the valve mechanism is removed during operation of the engine, the fuel passing through the flow fuse exceeds a certain flow rate (the pressure difference between the upstream side and the downstream side of the flow fuse exceeds a predetermined value), and the flow fuse overflows. The safety mechanism operates to shut out the fuel spill.
[0007]
According to the fuel injection device of the second aspect, the first pressure accumulator for storing the pressurized fuel, and the fuel pressurized to a pressure higher than the fuel pressure stored in the first pressure accumulator. A second pressure accumulator to be stored, a fuel injection valve that opens when the fuel is supplied from these pressure accumulators to inject the fuel, and the first pressure accumulator and the second pressure accumulator from the second pressure accumulator. A fuel supply passage for supplying fuel to the fuel injection valve, a first valve mechanism connected to the fuel supply passage for intermittently supplying fuel from the first accumulator to the fuel injection valve, and the fuel supply passage A second valve mechanism connected to the second pressure accumulator for intermittently supplying fuel to the fuel injection valve from the second pressure accumulator, the first pressure accumulator and the first valve mechanism Between the second pressure accumulator and the second valve mechanism. Respectively, wherein the flow fuse is provided with an over-spill safety mechanism.
[0008]
In this fuel injection device, a flow fuse having an overflow safety mechanism that shuts off the passage of fuel when the fuel passing therethrough exceeds a certain flow rate (the pressure difference between the upstream side and the downstream side exceeds a predetermined value) is used. , Provided between the accumulator and the valve mechanism, and each valve mechanism is configured to be detachable from the corresponding accumulator and the flow fuse.
Therefore, if the valve mechanism is removed during operation of the engine, the fuel passing through the flow fuse will exceed a certain flow rate (the pressure difference between the upstream and downstream sides of the flow fuse will exceed a predetermined value), and the safety of the flow fuse will be reduced. The mechanism operates to shut off the outflow of fuel.
Further, even if one of the valve mechanisms is inoperative due to a failure or the like and the fuel supply from one of the pressure accumulators is stopped, the fuel can be supplied from the other pressure accumulator, and engine stoppage can be avoided. At the same time, the valve mechanism can be replaced.
[0009]
According to the fuel injection device described in claim 3, in the fuel injection device described in claim 1 or 2, the pressure accumulator, the valve mechanism, and the flow fuse are configured as one unit. Features.
[0010]
In this fuel injection device, the accumulator, the valve mechanism, and the flow fuse are configured as one unit, and replacement and maintenance can be performed for each unit.
Further, since a unit composed of an accumulator, a valve mechanism, and a flow fuse can be connected to a fuel supply pipe by a fuel supply path (for example, a high-pressure pipe), this unit can be appropriately installed at a desired place. It becomes.
[0011]
According to the fuel injection device described in claim 4, in the fuel injection device described in claim 3, the valve mechanism is configured as a further unit, and is attached to and detached from the accumulator and the flow fuse. It is characterized in that it is configured to be possible.
[0012]
In this fuel injection device, the valve mechanism is configured as one further unit, and is configured to be detachable from the corresponding pressure accumulator and flow fuse, so that only the valve mechanism can be replaced.
[0013]
According to a fifth aspect of the present invention, there is provided a diesel engine including the fuel injection device according to any one of the first to fourth aspects, and a cylinder head to which the fuel injection valve is attached. I do.
[0014]
In this diesel engine, since a flow fuse is provided between the accumulator and the valve mechanism, it is possible to remove the valve mechanism and attach another new valve mechanism during operation of the engine.
That is, the valve mechanism can be replaced during the operation of the engine.
[0015]
According to the diesel engine described in claim 6, in the diesel engine described in claim 5, the unit including the accumulator, the valve mechanism, and the flow fuse is provided separately from the cylinder head. It is characterized by having.
[0016]
In this diesel, by providing a unit including a pressure accumulator and a valve mechanism separately from the cylinder head, maintenance, replacement of parts, and the like can be easily performed. Further, the degree of freedom in designing the diesel engine is increased, and the size and weight of the cylinder head or the diesel engine itself can be reduced.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a fuel injection device according to the present invention and a diesel engine including the same will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, a fuel injection device 10 includes a low-pressure accumulator (first accumulator) 11, a high-pressure accumulator (second accumulator) 12, and a low-pressure accumulator 11. A first control valve (first valve mechanism) 13 for interrupting fuel to the fuel injection valve 15; a second control valve (second valve mechanism) 14 for interrupting fuel to the fuel injection valve 15 from the high-pressure accumulator 12; , A fuel injection valve 15, a fuel supply passage 16, a first booster pump 17, a second booster pump 18, and flow fuses 24 and 25 as main elements.
[0018]
The low-pressure accumulator 11 is for storing the fuel whose pressure has been increased to, for example, 600 bar by the first pressure increasing pump 17.
Similarly, the high-pressure accumulator 12 is for storing fuel (for example, C heavy oil) pressurized to, for example, 1600 bar by the second pressurizing pump 18.
In the figure, reference numerals 17a and 18a denote filters for removing impurities from the fuel sucked into the first boosting pump 17 and the second boosting pump 18, respectively.
Reference numeral 19 denotes a fuel service tank.
[0019]
The first control valve 13 is configured to supply the fuel from the low-pressure accumulator 11 to the fuel injection valve 15, and to shut off the fuel supply to the fuel injection valve 15 and supply the residual pressure remaining on the fuel injection valve 15 side to the outside of the system. A three-way valve that can select a release position is used.
The second control valve 14 uses a two-way valve that can select a position for supplying fuel from the high-pressure accumulator 12 to the fuel injection valve 15 and a position for cutting off the fuel supply to the fuel injection valve 15.
[0020]
Further, when the position for cutting off the fuel supply to the fuel injection valve 15 is selected, the first control valve 13 discharges the fuel remaining in the fuel supply passage 16 on the side of the fuel injection valve 15 and generating an excess pressure. A drain discharge path 20 is connected, and a fuel drain tank 21 that receives excess fuel is provided downstream of the drain discharge path 20.
The drain discharge path 20 is provided with an equal pressure valve 22, and the fuel pressure in the drain discharge path 20 and the fuel supply path 16 on the upstream side of the equal pressure valve 22 is adjusted so as not to become lower than, for example, 200 bar. Have been.
On the other hand, a check valve 23 is provided in the fuel supply passage 16 that communicates the low-pressure accumulator 11 with the first control valve 13, and fuel located downstream of the check valve 23 is used for low-pressure. It does not flow backward to the pressure accumulator 11.
[0021]
The first control valve 13 and the second control valve 14 are operated by supplying hydraulic oil from a hydraulic oil tank through a hydraulic oil supply pump, a hydraulic oil supply pipe, and a hydraulic oil pilot valve. It is a hydraulically operated valve. The hydraulic oil pilot valve is an electromagnetic valve, and the valve opens and closes depending on whether or not current is supplied to the coil.
That is, the positions of the first control valve 13 and the second control valve 14 are operated by supplying or shutting off hydraulic oil by opening and closing the electromagnetic valves.
[0022]
The fuel injection valve 15 opens when fuel having a pressure equal to or higher than a predetermined pressure (for example, 450 bar) is supplied, and injects fuel into the cylinder. The fuel injection valve 15 is biased by a spring 15a in a direction in which the needle valve 15b is closed, and when a predetermined pressure is applied below the needle valve 15b, the fuel injection valve 15 overcomes the biasing force of the spring 15a to open the needle valve 15b. It is.
[0023]
The flow fuses 24 and 25 have an overflow safety mechanism that shuts off the passage of fuel when the fuel passing therethrough exceeds a certain flow rate (the pressure difference between the upstream side and the downstream side exceeds a predetermined value). . These flow fuses 24 and 25 are provided between the pressure accumulators 11 and 12 and the valve mechanisms 13 and 14, respectively.
[0024]
The low-pressure accumulator 11 and the fuel service tank 19 are connected by a communication pipe 26, and a relief valve 27 is provided in the communication pipe 26.
[0025]
The opening and closing of the first control valve 13 and the second control valve 14 are appropriately controlled by a control device (control means) (not shown).
[0026]
FIG. 2 is a schematic configuration diagram of a reciprocating diesel engine 30 including the fuel injection device 10.
2, reference numeral 31 denotes a cylinder, 32 denotes a cylinder head, 33 denotes a piston, 34 denotes a connecting rod, 35 denotes a crankshaft, 36 denotes a crankcase, and 37 denotes a valve.
[0027]
In the fuel injection device 10, the fuel injection valve 15 is installed substantially at the center of the cylinder head 32, but the low pressure accumulator 11, the high pressure accumulator 12, the first control valve 13, the second control valve 14, and the flow Fuses 24 and 25 are provided as one unit U1 separately on the side of the cylinder head 32 or the cylinder 31, and both are connected by a pipe (for example, a high-pressure pipe) forming the fuel supply path 16.
[0028]
As described above, the low-pressure accumulator 11, the high-pressure accumulator 12, the first control valve 13, the second control valve 14, and the flow fuses 24 and 25 are configured as one unit U1 separately from the fuel injection valve 15. And the cylinder head 32 or the cylinder 31 are provided separately, so that replacement of each unit U1 can be performed, and maintainability can be improved.
In addition, the degree of freedom in designing the diesel engine is increased, and the size and weight of the cylinder head, the cylinder, and the diesel engine can be reduced.
Further, this unit can be mounted instead of the fuel injection pump used in the conventional mechanical fuel injection valve, and the main injection system can be easily mounted.
[0029]
On the other hand, the first control valve 13 and the second control valve 14 are configured as one further unit U2, and are detachably attached to the low-pressure accumulator 11, the high-pressure accumulator 12, and the flow fuses 24 and 25. It is configured.
[0030]
With this configuration, the unit U2 including the first control valve 13 and the second control valve 14 can be replaced even during engine operation in the following procedure.
First, the operation of the solenoid valves of the first control valve 13 and the second control valve 14 to be replaced is stopped, and the hydraulic oil supply valve provided in the hydraulic oil supply pipe is closed.
A fixing member (for example, a bolt or the like) for fixing the unit U2 constituted by the first control valve 13 and the second control valve 14 to the low-pressure accumulator 11, the high-pressure accumulator 12, and the flow fuses 24 and 25. , And the unit U2 including the first control valve 13 and the second control valve 14 is removed from the low-pressure accumulator 11, the high-pressure accumulator 12, and the flow fuses 24 and 25.
At this time, the fuel passing through the flow fuses 24 and 25 exceeds a certain flow rate, and the supply of fuel is cut off. That is, fuel is supplied to the other cylinders, and the fuel is not supplied to the cylinders.
[0031]
Next, in place of the removed unit U2, a new unit U2 or a repaired unit U2 is attached via a fixing member.
After the installation is completed, the fuel pressure in the low-pressure accumulator 11 is reduced by opening a relief valve 27 provided in the middle of a communication pipe 26 that connects the low-pressure accumulator 11 and the fuel service tank 19. Thereby, the pressure difference between the upstream side and the downstream side of the flow fuse 24 provided between the low-pressure accumulator 11 and the first control valve 13 is reduced to a set value or less, and the flow fuse 24 is returned.
In this case, since the fuel pressure in the low-pressure accumulator 11 attached to another cylinder is also reduced, the fuel injection amount is also reduced as a whole. Therefore, it is necessary to advance the opening timing of the first control valve 13 or the second control valve 14 in order to compensate for the decrease in the fuel injection amount.
When the flow fuse 24 provided between the low-pressure accumulator 11 and the first control valve 13 returns, the relief valve 27 is closed to return the fuel pressure in the low-pressure accumulator 11 to a normal value. .
The previously closed hydraulic oil supply valve is opened, and the solenoid valve is returned to operation. When the operation of the solenoid valve is restored, the downstream side of the flow fuse 25 provided between the high-pressure accumulator 12 and the second control valve 14 when the first control valve 13 and the second control valve 14 are both opened. Then, the fuel pressure is applied from the low-pressure accumulator 11, the differential pressure between the upstream side and the downstream side of the flow fuse 25 becomes equal to or less than the set value, and the flow fuse 25 is returned.
When the flow fuses 24 and 25 return, they are returned to the state before removal, and the replacement operation ends.
[0032]
Thus, the unit U2 including the first control valve 13 and the second control valve 14 can be replaced without stopping the engine.
Therefore, even if the first control valve 13 and / or the second control valve 14 is broken, the stop of the engine can be avoided, and the reliability of the engine can be improved.
[0033]
In the embodiment described with reference to FIGS. 1 and 2, two pressure accumulators (11, 12), two control valves (13, 14), and two flow fuses (24, 25) are provided.
However, the present invention is not limited to this, and can be applied to a device having one accumulator, one control valve, and one flow fuse.
That is, the present invention can also be applied to a configuration in which the filter 18a, the second booster pump 18, the high-pressure accumulator 12, the flow fuse 25, and the second control valve 14 in FIG. 1 are omitted. In this case, the unit U2 is configured by the first control valve 13, and is configured to be detachable from the accumulator 11 and the flow fuse 24. The pressure in the pressure accumulator 11 is raised to, for example, 1600 bar.
[0034]
Further, in the above-described embodiment, a boosting pump is provided for each accumulator, but the present invention is not limited to this. For example, the boosting pump provided for the low-pressure side accumulator 11 is provided. The pump 17 can be omitted, and the fuel that has been pressurized from the booster pump 18 provided for the high-pressure accumulator 12 can be supplied to the low-pressure accumulator 11 through a pressure reducing means such as a pressure reducing valve or an orifice. .
[0035]
Further, after the first control valve 13 and the second control valve 14 are closed, the fuel remaining in the fuel supply passage 16 on the side of the fuel injection valve 15 and generating excess pressure is discharged through the drain discharge passage 20 and the fuel drain is discharged. It is to be collected in the tank 21. However, the present invention is not limited to this, and can be returned to the fuel service tank 19 again.
[0036]
Furthermore, although the control valves 13 and 14 are each hydraulically operated valves, the present invention is not limited to this, and may be simple electromagnetic valves.
That is, the control valves 13 and 14 may be any valves as long as they can switch the flow paths as described above.
However, when using heavy fuel oil or the like, which has a high viscosity and must be heated at the time of use, as the fuel, it is desirable to use hydraulically operated valves as the control valves 13 and 14. This is because, when using heated C heavy oil as fuel, if solenoid valves are used as these control valves 13 and 14, wiring may cause malfunctions due to heat or may be damaged by heat. Because.
[0037]
【The invention's effect】
According to the fuel injection device of the present invention and the diesel engine having the same, the following effects can be obtained.
According to the fuel injection device of the first aspect, even if the valve mechanism is removed during operation of the engine, the outflow of fuel is blocked by the flow fuse, so that the valve mechanism can be replaced without stopping the engine.
Therefore, even if the valve mechanism is broken, the stop of the engine can be avoided, and the reliability of the engine can be improved.
[0038]
According to the fuel injection device of the second aspect, even if the valve mechanism is removed during operation of the engine, the flow fuse blocks outflow of fuel, so that the valve mechanism can be replaced without stopping the engine.
Therefore, even if the valve mechanism is broken, the stop of the engine can be avoided, and the reliability of the engine can be improved.
Further, even if one of the valve mechanisms is inoperative due to a failure or the like and the fuel supply from one of the pressure accumulators is stopped, the fuel can be supplied from the other pressure accumulator, and engine stoppage can be avoided. At the same time, the valve mechanism can be replaced.
[0039]
According to the fuel injection device of the third aspect, since the pressure accumulator, the valve mechanism, and the flow fuse are configured as one unit, maintenance and replacement work for each unit can be easily performed.
Further, since a unit composed of an accumulator, a valve mechanism, and a flow fuse can be connected to a fuel supply pipe by a fuel supply path (for example, a high-pressure pipe), this unit can be appropriately installed at a desired place. Therefore, the maintainability and workability of the diesel engine can be improved, the reliability of the engine can be improved, and the work efficiency can be improved.
Further, the fuel injection pump can be replaced with a fuel injection pump used in a conventional mechanical fuel injection valve, and the present injection system can be easily mounted.
[0040]
According to the fuel injection device of the fourth aspect, the valve mechanism is configured as one further unit, and is configured to be detachable from the corresponding pressure accumulator and the flow fuse. It can be replaced, so that maintenance can be improved and costs can be reduced.
[0041]
According to the diesel engine of the fifth aspect, since the flow fuse is provided between the accumulator and the valve mechanism, it is possible to remove the valve mechanism during operation of the engine and attach another new valve mechanism. it can.
That is, the valve mechanism can be replaced even during engine operation.
[0042]
According to the diesel engine of the sixth aspect, since the pressure accumulator and the valve mechanism are provided separately from the cylinder head, maintenance, replacement of parts, and the like can be easily performed.
Further, the degree of freedom in designing the diesel engine is increased, and the size and weight of the cylinder head or the diesel engine itself can be reduced.
Further, since a conventional mechanical fuel injection valve can be used, it can be easily mounted on an engine using a mechanical fuel injection valve that has been manufactured without modifying the cylinder head.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a fuel injection device according to the present invention.
FIG. 2 is a schematic configuration diagram of a diesel engine equipped with the fuel injection device of FIG.
[Explanation of symbols]
10 Fuel injection device 11 Low pressure accumulator (first accumulator)
12 High pressure accumulator (second accumulator)
13 First control valve (first valve mechanism)
14 Second control valve (second valve mechanism)
15 Fuel Injection Valve 16 Fuel Supply Path 17 First Boost Pump 18 Second Boost Pump 24 Flow Fuse 25 Flow Fuse 30 Diesel Engine 32 Cylinder Head U1 Unit U2 Unit

Claims (6)

A pressure accumulator for storing pressurized fuel, a fuel injection valve that opens when the fuel is supplied from the pressure accumulator to inject the fuel, and supplies fuel from the pressure accumulator to the fuel injection valve In a fuel injection device, comprising: a fuel supply path, and a valve mechanism connected to the fuel supply path to intermittently supply fuel to the fuel injection valve.
A fuel injection device, wherein a flow fuse having an overflow safety mechanism is provided between the pressure accumulator and the valve mechanism. A first pressure accumulator for storing pressurized fuel,
A second pressure accumulator that stores fuel that has been boosted to a pressure higher than the fuel pressure stored in the first pressure accumulator,
A fuel injection valve that opens and injects the fuel by supplying the fuel from the accumulators;
A fuel supply path for supplying fuel from the first pressure accumulator and the second pressure accumulator to the fuel injection valve,
A first valve mechanism that is connected to the fuel supply path to intermittently supply fuel to the fuel injection valve from the first pressure accumulator;
A second valve mechanism connected to the fuel supply path to intermittently supply fuel from the second pressure accumulator to the fuel injection valve,
A flow fuse having an overflow safety mechanism is provided between the first pressure accumulator and the first valve mechanism, and between the second pressure accumulator and the second valve mechanism, respectively. A fuel injection device. The fuel injection device according to claim 1 or 2,
The fuel injection device, wherein the accumulator, the valve mechanism, and the flow fuse are configured as one unit. The fuel injection device according to claim 3,
The fuel injection device, wherein the valve mechanism is configured as one further unit, and is configured to be detachable from the accumulator and the flow fuse. A fuel injection device according to any one of claims 1 to 4,
A cylinder head to which the fuel injection valve is attached. The diesel engine according to claim 5,
A diesel engine, wherein the unit including the accumulator, the valve mechanism, and the flow fuse is provided separately from the cylinder head.

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