JP3021259B2 - Fuel / water injection device - Google Patents

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 As a means for simultaneously reducing NO ₂ in exhaust gas of a diesel engine, suppressing black smoke emission and reducing fuel consumption rate, one fuel injection valve burns fuel and water at the same time. It is effective to inject the fuel into the room and burn it. An example of the means is a fuel / water injection device as shown in FIG. The configuration will be described with reference to FIG. In the figure, 01 is a fuel tank, 02 is a combustion supply pump, 050 is a fuel injection pump, 03 is the same body, 04
Is the same plunger, 05 is the same barrel, 06 is the same discharge valve, 0
7 is a check pressure regulating valve, and 08 is a fuel injection pipe. 040 is a fuel injection valve, 09 is the same body, 010 is an injection hole, 011 is a needle valve, 012 is an oil reservoir, 013 is a waterway check valve, 014 is a biasing spring for a needle valve, 021 is a water passage in the injection valve, 022 is An oil passage in the injection valve, 030 is a communication passage between the water passage and the oil passage, and 031 is a junction of the injected water and fuel. 0101 is a hydraulic oil tank, and 0102 is a hydraulic oil pump. 0201 is a water tank, 0202 is a water supply pump, 0203 is a water supply check valve for suppressing backflow to the water supply pump, 0204 is a water injection check valve for suppressing backflow to an actuator 0301 in the water injection unit 0300 described below, Reference numeral 0205 denotes a water supply connection pipe.

[0003] Reference numeral 0300 denotes a water injection unit composed of the following components. Reference numeral 0301 denotes an actuator, and an oil-tightly sealed slidable spool 0 is provided in the cylinder.
302 has been inserted. 0303 is the spool 0302
The set position can be adjusted by the stroke adjuster 0304 to change the spool stroke S. Reference numeral 0305 denotes an electromagnetic hydraulic oil switching valve which uses a two-port electromagnetic spool valve. Reference numeral 0400 denotes a controller for controlling the start and stop of the water supply pump 0202 and the hydraulic oil pump 0102, and for controlling the amount and timing of water injection into the fuel injection valve 040. Load signal, crankshaft TD
There is a C signal and a crank angle signal. Reference numeral 0501 denotes a water supply pump driving device, and reference numeral 0502 denotes a hydraulic oil pump driving device. Control signals to these driving devices are output from the controller 0400.

Next, the operation will be described. The engine is started by injection of only fuel and enters a steady operation state. When the operation by fuel / water injection becomes possible, the water supply pump 0202 and the hydraulic oil pump 0102 are operated. At this time, an engine speed signal and an engine load signal are input to the controller 0400 as information on the operation state of the engine, and the amount of water injection corresponding to the operation state of the engine is calculated, and the spool 030 that regulates the amount of water injection is controlled.
The second stroke S is set by adjusting the position of the stopper 0303 by the stroke adjuster 0304. Also,
The operation timing of the electromagnetic oil switching valve 0305 is set and operated based on the engine speed signal, the crankshaft TDC signal, and the crank angle signal input to the controller 0400.

[0005] Here, the feed water pressure P _W, hydraulic fluid pressure P _L, the valve opening pressure P _S of the water supply check valve 0203, opening pressure P _P waterway check valve 013 and water injection check valves 0204 check regulator valve There is the following relationship between the valve opening P _{R of} 07 and the valve opening pressure P _O of the needle valve 011. _{P S <P W <P L} P R <P P < feedwater pressure P _W to pressurized water P _O water supply pump 0202 to open the water supply check valve 0203 opening pressure P _S, the water injection It is supplied to the space between the spool 0302 and the stopper 0303 in the actuator 0301 of the unit 0300. When the electromagnetic hydraulic oil switching valve 0305 is operated by an instruction signal from the controller 0400, the hydraulic oil pump 010
Hydraulic oil pressurized to the pressure P _L at 2 is the spool 0302
Acts on the back. Since the hydraulic oil pressure P _L is higher than the feed water pressure P _{W, the} water supplied to the space portion is
Although 02 pressurized extruded from the actuator 0301 so the water supply check valve 0203 is closed, the valve opening pressure P _P of irrigation check valve 0204 and the fuel injection valve 040 opens the water channel check valve 013 Injected into channel 21. The water injected from the water channel 021 flows from the communication channel 030 to the junction 03
Through 1 flows into the oil passage 022 in the fuel injection valve 040, the fuel in the oil passage 022 and the fuel injection pipe 08 by the inflow is pushed back to the fuel injection pump 050 side, the check pressure regulating valve valve opening pressure P _R 07 is released and returned into the barrel 05 of the injection pump.

[0006] When the discharge of the predetermined amount of water is completed, the spool 0302 comes into contact with the stopper 0303. Subsequently, when the excitation of the electromagnetic oil switching valve 0305 is released, the spool 030
2 of working oil pressure P _L acting on the rear hydraulic oil tank through the discharge side flow passage of the hydraulic oil switching valve 0305 01
01, the spool 0302 returns to the original position by the pressure _{PW of} the supply water flowing into the front surface thereof, and waits for the next cycle. The water injection into the fuel injection valve 040 is performed at a time when the fuel is not discharged from the fuel injection pump 050. At the time of the completion of water injection, the fuel remaining in the previous cycle, the water injected into the upstream portion thereof, and the upstream portion thereof flow into the oil passage 022 of the injection valve from the oil reservoir 012 at the downstream portion to the lower portion of the junction portion 031. There is a fuel pushed back by the injection water, and a stratified liquid column is formed by the fuel and the water.

When the fuel injection timing comes, the plunger 04 of the fuel injection pump 050 is pushed up by a cam (not shown) to pressurize the fuel in the barrel 05, the discharge valve 06 is opened, and the fuel injection valve 040 is opened via the fuel injection pipe 08. Oilway 022
Fuel is pumped inside. When the fuel pressure acts on the needle valve 011 having the valve opening pressure P _O and the force becomes equal to or greater than the urging force of the spring 014, the needle valve 011 is opened, and the oil reservoir 012 is first opened from the injection port 010.
The fuel and water that have formed a stratified liquid column in the order of the residual fuel in the portion, the water injected into the oil passage 22, and then the fuel on the upstream side of the injected water are injected into the combustion chamber, and one cycle of fuel is injected.・ Water injection is completed.

[0008]

In the fuel / water injection device described above, the amount of fuel and water injected into the combustion chamber is defined by the position of the injection amount control rack of the fuel injection pump, and the load and rotation of the engine are controlled. It is usually controlled by a governor so that the injection quantity matches the number. In such a device, when a malfunction occurs in the water supply system and there is a cylinder in which water is not completely injected, if the operation is continued while the position of the control rack of the fuel injection pump is kept as it is, the water in the cylinder is not affected. As a result, the fuel injection amount is increased by the amount of no fuel injection, and an abnormal increase in the cylinder internal pressure and a fuel failure due to an insufficient amount of air cause an abnormal increase in the exhaust gas temperature and the generation of black smoke.

An object of the present invention is to solve the above-mentioned problems, and to be applied to a multi-cylinder engine. If there is a cylinder in which a failure has occurred in the water injection system, an alarm is issued and the fuel injection amount to the cylinder is suppressed. Fuel and water injection that can suppress abnormal rises in cylinder pressure and exhaust temperature, prevent the generation of black smoke, and if the number of abnormal cylinders exceeds the set number, shift to operation using fuel only injection In providing the device.

[0010]

As described above, when an abnormality occurs in the water injection system and the water injection is not completely performed,
The amount of fuel to be injected increases, and the exhaust gas temperature rises. Utilizing this, the exhaust gas temperature at each cylinder outlet and the exhaust gas temperature at the turbocharger inlet or the collecting part are measured, and the temperature change rate with respect to the time is calculated. Comparing the deviation from the rate of change of the exhaust temperature at the inlet or at the collecting part, and when the value exceeds a preset value, the cylinder is determined to be abnormal and an exhaust temperature alarm is displayed, and the fuel control rack is controlled to reduce the fuel. I do. Furthermore, when the number of abnormal cylinders increases and exceeds the set number of cylinders, the water supply pump, hydraulic oil pump, and electromagnetic hydraulic oil switching valve are stopped, and the limit drive unit for the fuel injection amount control rack is released. The operation can be shifted to the operation by injection of only the fuel.

[0011]

[Action] Exhaust temperature alarm device, fuel rack limit drive device,
FIG. 3 is a block diagram showing a configuration of a controller for controlling the water supply pump driving device, the hydraulic oil pump driving device, and the water injection unit, and the operation thereof will be described. When the exhaust gas temperature at each cylinder outlet and the exhaust gas temperature at the turbocharger inlet or the collecting section are input to the controller, the temperature change rate with respect to time is calculated. The temperature change rate at each cylinder outlet is compared with a preset value, and the deviation between the temperature change rate at each cylinder outlet and the turbocharger inlet or collecting part exhaust temperature change rate is a preset value. Then, it is determined whether the operation is normal or abnormal. When the abnormal cylinder is specified, the abnormal cylinder temperature is output to the exhaust temperature alarm device to notify the abnormal exhaust temperature of the cylinder. Further, the abnormal cylinder number comparator compares the number of cylinders set in the abnormal cylinder number storage unit with the abnormal cylinder number. If the number of abnormal cylinders is smaller than the set number of cylinders, the fuel injection amount is limited by the fuel rack restriction driving device for the cylinder in which the abnormality has occurred, based on a signal from the abnormal cylinder determination unit.

When the number of abnormal cylinders increases and exceeds the set number of cylinders, it is determined that the operation by injecting water is no longer possible, and the water supply pump is stopped by a signal from the water supply pump driving device. The hydraulic oil pump is stopped by a signal from the hydraulic oil pump driving device, and the electromagnetic hydraulic oil switching valve is further stopped by a signal from the water injection unit. At the same time, the restriction on the movement of the injection amount control rack made on the abnormal cylinder by the signal from the abnormal cylinder determiner is released.

[0013]

FIG. 1 shows a configuration diagram of a fuel / water injection device according to an embodiment of the present invention. The configuration will be described with reference to the drawings. In the figure, 1 is a fuel tank, 2 is a fuel supply pump, 50 is a fuel pump, 3 is the same body, 4 is a plunger, 5 is the same barrel, 6 is the same discharge valve, 7 is a check pressure regulating valve, 8
Is a fuel injection pipe. 40 is a fuel injection valve, 9 is the same body,
10 is a nozzle, 11 is a needle valve, 12 is an oil reservoir, 13 is a waterway check valve, 14 is a biasing spring for setting valve opening pressure, 21 is a water passage in the injection valve, 22 is an oil passage in the injection valve, and 30 is an oil passage in the injection valve. The communication passage 31 between the water passage and the oil passage is a junction of the fuel and the injected water. 101
Denotes a hydraulic oil tank, and 102 denotes a hydraulic oil pump. 201
Is a water tank, 202 is a water supply pump, 203 is a water supply check valve for suppressing backflow to the water supply pump, 204 is a water injection check valve for suppressing backflow to the actuator 301 in the water injection unit 300, and 205 is a water supply connection Tube.

Reference numeral 300 denotes a water injection unit, and reference numeral 301 denotes an actuator into which an oil-tightly sealed slidable spool 302 is inserted. Reference numeral 303 denotes a stopper for the spool 302, which can adjust its set position by a position stroke adjuster 304 to change the spool stroke S. Reference numeral 305 denotes a two-port electromagnetic oil switching valve. 400 is a controller,
An engine speed signal, an engine load signal, a crankshaft TDC signal, and a crank angle signal are input. 501
Is a water supply pump driving device, 502 is a hydraulic oil pump driving device, 503 is a fuel rack limiting driving device of a fuel injection pump, and is a device for controlling a fuel injection amount of an arranged cylinder.
Although not shown, there is, for example, one shown in Japanese Patent Application No. 03-207147. Reference numeral 600 denotes an exhaust temperature alarm device for displaying and notifying an abnormal cylinder.

Next, FIG. 2 shows an embodiment of a six-cylinder power generating diesel engine, and the overall configuration will be described.
1 is a fuel tank, 2 is a fuel supply pump, and 50 is a fuel injection pump. 101 is a hydraulic oil tank, 102 is a hydraulic oil pump, 201 is a water tank, 202 is a water supply pump,
The piping from the hydraulic oil pump and the water supply pump is connected to the water injection unit 300. Reference numeral 401 denotes an engine speed signal sensor, 402 denotes an engine load signal sensor, 403 denotes a crank angle signal sensor, and 404 denotes a crankshaft TDC signal sensor which is input to the controller 400. 500 is a 6-cylinder power generation diesel engine, 501 is a flywheel, and 502 is a generator. Reference numeral 503 denotes a fuel rack limiting drive device of the fuel injection pump. 601 to 60
Up to 6, an exhaust gas temperature sensor attached to the exhaust pipe of each cylinder, 700 is an exhaust gas temperature sensor at the inlet of the supercharger, and a signal detected by each sensor is a controller 400.
Is input to

Next, the operation will be described with reference to FIGS. The water supply pump and the hydraulic oil pump are operated to a predetermined pressure. At this time, the water is supplied by water
03 and the spool 3 in the actuator 301
02 is supplied to the front space. Controller 400
When the electromagnetic operating oil switching valve 305 is operated by an instruction from the operator, the operating oil pressure acts on the rear surface of the spool 302. Since the pressure of the hydraulic oil is higher than the pressure of the supply water, the water that has been supplied earlier is moved by the spool 302 to the actuator 301.
However, since the water supply check valve 203 is closed,
The water pushes the injection check valve 204 and the waterway check valve 13,
The oil is injected into the oil passage 22 through the water passage 21, the communication passage 30, and the junction 31. The oil passage 22 and the fuel injection pipe 8 are
The fuel inside is pushed back to the fuel injection pump 50 side and pushes the check pressure regulating valve 7 back to the inside of the barrel 5. Spool 30
2 comes into contact with the stopper 303 when the discharge of the predetermined amount of water is completed. After that, when the excitation of the electromagnetic hydraulic oil switching valve 305 is released, the hydraulic oil acting on the rear surface of the spool is discharged to the tank, so that the pressure decreases, and the spool 302 returns to the original position by the water pressure acting on the front surface. Then, it enters a standby state for the next cycle. The water injection into the injection valve is performed at a time when the fuel is not discharged from the fuel injection pump 50.

At the fuel injection timing, the plunger 4 is pushed up by a cam (not shown) to compress the fuel in the barrel 5, push the discharge valve 6, and the pressure is transmitted to the fuel injection pipe 8. Further, when the pressure of the oil reservoir 12 becomes higher than the valve opening pressure of the needle valve 11, the residual fuel in the oil reservoir, the water injected into the oil passage 22 and then further upstream of the injected water from the injection port 10 at the tip. The fuel and water are injected into the combustion chamber in the order of the fuel on the side, completing one cycle of fuel / water injection. In the fuel / water injection device having such a configuration and function, when a failure occurs in the water injection system and the exhaust temperature rises abnormally as described in the section of [Action], an exhaust temperature alarm signal is output, and If the number of abnormal cylinders increases and exceeds the set number of cylinders, the operation of the water supply pump, hydraulic oil pump, and electromagnetic hydraulic oil switching valve is stopped, and the fuel The limiting drive is released so that operation can be shifted to normal fuel-only operation.

[0018]

According to the present invention, if there is a malfunctioning cylinder in the water injection system, an exhaust temperature alarm signal is output and the amount of fuel injected into the cylinder is suppressed. , The abnormal increase in the cylinder pressure and the exhaust gas temperature can be suppressed, and the generation of black smoke can be prevented. Further, when the number of abnormal cylinders exceeds the set number, the operation can be shifted to a normal operation by injection of only fuel.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a fuel / water injection device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an embodiment in which the fuel / water injection device of the present invention is installed in a 6-cylinder diesel engine for power generation.

FIG. 3 is a block diagram showing a configuration of a controller in FIGS. 1 and 2;

FIG. 4 is a configuration diagram of a fuel / water injection device according to a conventional technique.

[Explanation of symbols]

40: fuel injection valve, 302: spool, 203: water supply check valve, 204: water injection check valve, 201: water tank, 202
... water supply pump, 101 ... hydraulic oil tank, 102 ... hydraulic oil pump, 300 ... water injection unit, 305 ... electromagnetic hydraulic oil switching valve, 400 ... controller, 501 ... water supply pump drive device, 502 ... hydraulic oil pump drive device, 600: exhaust temperature alarm device; 601-606: cylinder outlet exhaust temperature detector; 700: supercharger inlet exhaust temperature detector.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichi Hara 12 Nishikicho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) F02M 25/022 F02B 47/02 F02B 77/08

Claims (1)

(57) [Claims] In a fuel / water injection device applied to a multi-cylinder diesel engine and injecting fuel and water from a single fuel injection valve into a combustion chamber at the same time, a fuel / water injection device is provided at a fuel discharge portion of a fuel injection pump (50). Check pressure regulator installed (7)
A water channel (21) drilled in the fuel injection valve (40),
A water supply pump (2) provided in a communication passage (30) with the oil passage and a water passage check valve (13), and a water conduit from the water tank (201) to the water injection unit (300) and the fuel injection valve.
02), water supply check valve (203) and water injection check valve (20)
4), an actuator (301) and an electromagnetic hydraulic oil switching valve (305) constituting the water injection unit (300), and hydraulic oil to the back of the spool (302) in the actuator via the electromagnetic hydraulic oil switching valve. A hydraulic oil tank (101) and a hydraulic oil pump (102) serving as a pressure feed source, and signals about the engine speed, load, top dead center, crank angle, exhaust temperature at the cylinder outlet, and exhaust temperature at the turbocharger inlet are transmitted. A controller (400) to be input, a water supply pump driving device (501), a hydraulic oil pump driving device (502), a fuel rack control driving device (503), a water injection unit (300), and an exhaust gas from which signals are output from the controller. A temperature alarm device (600) for injecting fuel and water into the oil passage of the fuel injection valve at a time when fuel is not being discharged from the fuel injection pump. When there is a cylinder in which an abnormality has occurred in the water injection system, a layered liquid column is formed and an alarm is issued, the movement of the fuel injection control rack of the cylinder is restricted, and the number of cylinders in which the abnormality has occurred exceeds the set number. In the case of water injection unit operation and water supply pump of all cylinders,
The operation of the hydraulic oil pump is stopped, and the restriction on the movement of the fuel injection control rack is released, and the operation is shifted to the operation using only fuel injection.
Water injection device.