JPH06346812A - Fuel and water injection device - Google Patents

Abstract

PURPOSE:To prevent the fuel injection amount of an only abnormal cylinder from increasing even if any abnormal condition is generated in a water filling device, and prevent fault of an engine such as abnormal raising of cylinder inner pressure, abnormal raising of an exhaust temperature, and generation of graphite. CONSTITUTION:Motion of water filling spool 302 is detected per cycle, the fuel rack amount of a fuel pump 3 for each cylinder is reduced until the number of an abnormal cylinder in water filling device is in a number similar to that of a setting cylinder. When the number of the abnormal cylinder is increased and the number of the setting cylinder exceeds the number of the abnormal cylinder, driving of a water filling pump 202, an operating oil pump 102, and an electromagnetic spool valve 305 is stopped, and restriction of the fuel rack amount is released simultaneously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for a diesel engine.

[0002]

2. Description of the Related Art Fuel and water are supplied from a single fuel valve as a means of simultaneously reducing nitrogen oxides (NO _x ) in exhaust gas of a diesel engine and reducing engine exhaust black smoke and fuel consumption. It is effective to inject and burn at the same time. As a method thereof, there is one as shown in FIG. 3, and its outline will be described. In the figure, 01 is a fuel tank,
Reference numeral 02 is a fuel supply pump, and 03 is a fuel pump. 04
Is a fuel pump plunger, 05 is a plunger barrel, 0
6 is a discharge valve, 07 is a check pressure regulating valve, and 08 is an injection pipe.
Reference numeral 040 is a fuel injection valve, 09 is a fuel valve main body, 010 is a nozzle injection port, 011 is a needle valve, 012 is an oil reservoir, 013 is a check valve, and 014 is a spring for setting the valve opening pressure of the fuel valve needle valve. . Reference numeral 021 denotes a fuel valve internal water passage, 022 denotes a fuel valve internal oil passage, and the water passage and the oil passage communicate with each other at a confluence portion of 031 through a hole 030.

Reference numeral 0101 is a hydraulic oil tank, and reference numeral 0102 is a hydraulic oil pump. Reference numeral 0201 is a water tank, 0202 is a water pump, 0203 is a check valve for preventing reverse flow to the water pump, 02
Reference numeral 04 is a check valve for preventing backflow to the water injector, and reference numeral 0205 is a water connection pipe. Reference numeral 0300 is a water injection unit, which is an oil-tight seal in the cylinder of 0301, and is a slidable spool 030.
There are two. Reference numeral 0303 denotes a spool stopper, the position of which is changed by the stopper position adjuster 0304. 0305 is a solenoid spool valve. 0400
Is a controller, which receives a crankshaft TDC signal, a crank angle signal, an engine speed signal, and an engine load signal of the engine.

The operation of the conventional example will be described. The water pump and hydraulic oil pump are operating and are at the specified pressure. At this time, water pushes the check valve 0203 and is supplied to the space portion of the cylinder 0301. Solenoid spool valve 0
When the hydraulic oil pressure acts on the back surface of the spool when 305 operates (the hydraulic oil pressure is higher than the water supply pressure), the previously supplied water is pushed out by this, but the check valve 02
Since 03 is closed, the water pushes the check valves 020 4 and 013 to pass the water channels 021 and 030 and the confluence section 031 to the oil channel 02.
Injected into 2. At this time, the oil in the injection pipe is returned through the check pressure regulating valve 07. The spool 0302 discharges a predetermined amount and hits the stopper 0303. After that, when the electromagnetic spool valve 0305 is de-energized, the hydraulic pressure is released to the tank, so the pressure drops, and the hydraulic pressure returns to the original position to wait for the next discharge. These are performed at the time when fuel injection described below is not being performed.

Next, at a predetermined timing of fuel injection, the plunger 04 is raised by a cam (not shown),
The fuel is compressed, the discharge valve 06 is pushed open, and the pressure in the injection pipe 08 rises. Further, the pressure in the oil sump 012 is 0
When the pressure becomes higher than the valve opening pressure of 11, the fuel in the oil sump 012, the water injected into the oil passage 022, and the fuel are further injected from the tip injection port 010, burned in the cylinder, and push down the piston. do. The amount of fuel and water injected at this time is defined by the position of the control rack of the fuel pump, and is normally set by the governor so that the required fuel amount corresponds to the output of the engine.

[0006]

In such a device, when the spool of the water supply device becomes abnormal and water is not completely injected, if the control rack of the fuel pump is continuously operated with a constant level, The fuel injection amount of the cylinder increases as much as there is no water injection, which causes an abnormal rise in the cylinder pressure and a combustion failure due to insufficient air amount, which causes an abnormal rise in the exhaust temperature and the generation of black smoke.

The object of the present invention is to prevent an increase in the fuel injection amount only in the abnormal cylinder even if an abnormality occurs in the water injection device, to cause an abnormal rise in the cylinder pressure, an abnormal rise in the exhaust temperature, and the generation of black smoke. It is an object of the present invention to provide a fuel / water injection device that prevents problems for the engine.

[0008]

A fuel / water injection device of the present invention is applied to a multi-cylinder engine, and is a fuel injection device for a diesel engine in which fuel and water are simultaneously injected from one fuel valve. The check valve 2 for suction and discharge is provided on one side of a spool 302 that hermetically seals the supply of water to the sliding surface.
Water is supplied by a water pump from a water tank via 03 and 204, and the oil pressurized by the hydraulic oil pump 102 is discharged to the opposite side of the spool from the fuel pump 3 through the electromagnetic spool valve 305. In the case where the fuel is supplied at a certain time and the fuel pressure is used to simultaneously inject fuel and water;
A means for confirming the operation of the spool, and a means 50 for limiting the fuel rack amount of the cylinder if the spool is abnormal.
3 and when the number of abnormal cylinders is determined and exceeds the set value, the solenoid spool valves 305 of all cylinders and the operation of the hydraulic oil pump and the water pump are stopped, and when water injection of all cylinders is stopped. It is characterized by including a controller 400 for releasing the restriction of the fuel rack and returning it to a normal operating state.

[0009]

The fuel rack limiting device, water supply pump, and
A block diagram of the operation and stop of the hydraulic oil pump and the electromagnetic spool valve is shown in FIG. 2, and its operation will be described. In the controller, by the signal from the operation detector of the water injection piston,
It has a water injection piston operation determination unit that determines whether the operation of the water injection piston is normal, and further compares the number of cylinders set in the abnormal cylinder number storage unit with the abnormal cylinder number by an abnormal cylinder number comparator. To do.

If the number of abnormal cylinders is smaller than the set number of cylinders, the signal from the fuel rack limit cylinder determination section limits the fuel amount by the fuel rack limit drive device of the cylinder in which the abnormality occurs. The number of abnormal cylinders increases,
When the number of set cylinders is exceeded, it is determined that the operation with water injection is no longer possible, and the water pump is activated by the signal from the water pump drive determination unit, and the hydraulic pump is activated by the signal from the hydraulic oil pump drive determination unit. However, the water injection electromagnetic spool valve is stopped by a signal from the water injection electromagnetic spool valve drive determination unit. At the same time, the fuel rack limit cylinder determination unit is configured to release the limit of the fuel rack that has been set in the abnormal cylinder.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the present fuel / water injection device will be described in detail. In the figure, 1 is a fuel tank, 2 is a fuel supply pump, and 3 is a fuel pump. 4 is a fuel pump plunger, 5 is a plunger barrel, 6 is a discharge valve, 7 is a check pressure regulating valve, and 8 is an injection pipe. 40 is a fuel injection valve, 9 is a fuel valve main body, 10 is a nozzle injection port, 11 is a needle valve, 12 is an oil reservoir, 13 is a check valve, and 14 is a spring for setting the valve opening pressure of the fuel valve needle valve. . Reference numeral 21 is a fuel valve inner water passage, 22 is a fuel valve inner oil passage, and the water passage and the oil passage are communicated with each other at a confluence portion of 31 by a hole 30. Reference numeral 101 is a hydraulic oil tank, and 102 is a hydraulic oil pump. 201 is a water tank, 202 is a water pump, 2
Reference numeral 03 is a check valve for preventing backflow to the water pump, 204 is a check valve for preventing backflow to the water injector, and 205 is a water connection pipe.

A water injection unit 300 has a spool 302 which is oil-tightly sealed and slidable in a cylinder of 301. Reference numeral 303 denotes a spool stopper, the position of which is changed by a stopper position adjuster 304.
305 is an electromagnetic spool valve, and 306 is an operation detector of the spool 302. Reference numeral 400 denotes a controller, which receives (1) crankshaft TDC signal, (2) crank angle signal, (3) engine speed signal, and (4) engine load signal of the engine. Reference numeral 501 is a water pump driving device, 502 is a hydraulic oil pump driving device, and 503 is a rack limiting device of a fuel pump, which reduces the fuel injection amount of the cylinder. Although not shown, for example, Japanese Patent Application No. 03-2071.
There is something like 47.

Next, the operation of the above embodiment will be described.
The water pump and hydraulic oil pump are operating and are at the specified pressure. At this time, water pushes the check valve 203 and is supplied to the space of the cylinder 301. Solenoid spool valve 3
When 05 operates, the hydraulic pressure acts on the back surface of the spool (the hydraulic oil pressure is higher than the water supply pressure), but the previously supplied water is pushed out by this, but the check valve 203 closes, so the water is Push the check valves 204 and 13 to open the water channel 2.
It is injected into the oil passage 22 through the junctions 31 and 31.
At this time, the oil in the injection pipe is returned through the check pressure adjusting valve 7 of the fuel pump 3. The spool 302 discharges a predetermined amount of water and hits the stopper 303. Then solenoid spool valve 3
When the excitation of 05 is released, the hydraulic pressure is released to the tank, so the pressure drops, and the hydraulic pressure returns to the original position to wait for the next discharge. This is performed at the time when the fuel injection described below is not being performed.

At this time, the operation detector 306 including a proximity switch or the like confirms the movement of the spool 302 every cycle and inputs it to the controller 400. Next, when the fuel injection comes at a predetermined timing, the fuel pump 3 (not shown)
The plunger 4 rises due to the cam and the like, the fuel is compressed, the discharge valve 6 is pushed open, and the pressure of the injection pipe 8 rises. Further, the pressure in the oil sump portion 12 of the fuel injection valve 40 is changed to the needle valve 1
When the valve opening pressure becomes higher than 1, the fuel in the oil sump portion 12, the water next injected into the oil passage 22 and the fuel are further injected from the tip injection port 10 and burned in the cylinder to push down the piston. do.

Further, in the fuel / water injection device having the structure and function as shown in FIG. 2 which is a block diagram, the operation of the water injection spool 302 is performed by the water injection piston detection unit 306 as described in the above section. Check the cycle, and in case of abnormality,
The fuel amount rack of the cylinder is limited via the controller 400, and if the number of abnormal cylinders exceeds the set number of cylinders, the water pump, the hydraulic oil pump, and the electromagnetic spool valve are stopped, and the fuel amount is further reduced. The restriction is lifted, and it operates so as to perform normal fuel-only operation.

[0016]

According to the present invention, even if an abnormality occurs in the water injection device, the fuel injection amount only in the abnormal cylinder is prevented from increasing, and the cylinder pressure abnormally rises, the exhaust temperature abnormally rises, and the black smoke is generated. It is possible to avoid trouble with the engine. When the number of abnormal cylinders exceeds the set value, water injection is stopped for all cylinders, and it is possible to return to the normal operating state with only fuel.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram of control according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a conventional device.

[Explanation of reference numerals] 40 ... Fuel valve, 302 ... Spool, 203, 204 ... Check valve, 201 ... Water tank, 202 ... Water pump, 101 ...
Operating oil tank, 102 ... Operating oil pump, 305 ... Electromagnetic spool valve, 306 ... Spool operation detector, 400 ... Controller, 501 ... Water pump drive device, 502 ... Operating oil pump drive device, 503 ... Fuel rack limit drive device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Hara 12 Nishiki-cho, Naka-ku, Yokohama, Kanagawa Mitsubishi Heavy Industries, Ltd.Yokohama Works (72) Shinji Yasuda 12 Nishiki-cho, Naka-ku, Yokohama, Kanagawa Mitsubishi Heavy Industries Yokohama Co., Ltd.

Claims (1)

[Claims] 1. A fuel injection device for a diesel engine, which is applied to a multi-cylinder engine and simultaneously injects fuel and water from one fuel valve, in which the water supply into the fuel valve is hermetically sealed on a sliding surface. Water is supplied by a water pump from a water tank to one side of the spool (302) through intake and discharge check valves (203) (204), and is pressurized by a hydraulic oil pump (102) on the opposite side of the spool. The oil is supplied through the electromagnetic spool valve (305) at a time when the fuel pump (3) is not discharging and the oil pressure is used to simultaneously inject fuel and water; means for confirming spool operation And (503) means for limiting the fuel rack amount of the cylinder when the spool is abnormal, and actuating and operating the electromagnetic spool valves of all the cylinders when the number of cylinders of the abnormal cylinder is determined and the set value is exceeded. When the operation of the oil pump and the water pump is stopped, and further, when the water injection of all the cylinders is stopped, the restriction of the fuel rack is released, and the controller (400) for returning to the normal operation state is provided. Water injection device.