JP3317202B2 - Fuel injection control device for accumulator type engine - 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 control device for an accumulator type engine used for a diesel engine or the like.

[0002]

2. Description of the Related Art Conventionally, an accumulator type fuel injection device is known as one of fuel injection devices for a diesel engine. This device accumulates high-pressure fuel from a supply pump in a pressure accumulating pipe called a common rail, and injects this into each cylinder of the engine by opening an injector.

[0003] As this kind of technology, for example, Japanese Patent Laid-Open No.
The thing disclosed in 207548 gazette is known.
In this technique, a pressure control valve is provided in a supply pump, and the pressure control valve is feedback-controlled using a cylinder discrimination signal, an NE pulse signal, and the like so that the fuel pressure in the common rail matches a target pressure.

[0004] By the way, when the start of the diesel engine is started, the fuel pressure in the common rail is generally reduced. For this reason, it is necessary to control the pressure control valve so as to increase the common rail pressure. However, since cylinder discrimination cannot be performed at the time of extremely low rotation such as at the time of starting the engine, the above-described technique requires the common rail Before the cylinder of the engine is determined, the pressure control valve is turned on and off with an anticipation in order to rapidly increase the fuel pressure inside the engine, thereby ensuring a high fuel pressure (full pressure feed control). According to this technique, the fuel pressure in the common rail can be more quickly increased at the time of starting.

[0005]

However, the above prior art has the following problems. That is,
Although the above technology is effective in that the fuel pressure in the common rail can be increased more quickly, it focuses solely on the on / off control of the pressure control valve in anticipation. However, the case where the target fuel pressure is exceeded has not been considered. For this reason, when the actual fuel pressure exceeds the target fuel pressure, atomization of the fuel after the engine is started becomes too good, and there is a possibility that an extremely loud combustion noise may be generated. .

[0006] Further, for a while after the operation of the engine is completed, the pressure in the common rail is still kept high. When the engine is restarted in such a state, the above-described problem is more likely to occur because the above-described full-pressure feeding control is performed before the cylinder discrimination.

Furthermore, there is a case where the starter for starting the engine by cranking is changed from an on state to an off state, and the engine does not start (starting fails). In such a case, the driver repeats the operation of turning on the starter again.However, in the above-described technology, since the full pressure control is performed from the time the starter is turned on until the cylinder is determined, the actual fuel pressure is reduced. ,
A situation in which the target fuel pressure is exceeded is extremely likely to occur, and as a result, the above-described problem has been more likely to occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a fuel injection control device for a pressure accumulating type engine, in which the fuel pressure in a pressure accumulating pipe is too high when starting the engine. An object of the present invention is to provide a fuel injection control device for a pressure-accumulation engine that can suppress generation of combustion noise.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, a high pressure fuel is supplied from a supply pump, and a pressure accumulating pipe for accumulating the high pressure fuel is connected to the pressure accumulating pipe. The fuel injection means for injecting fuel into the cylinder of the engine, the state detection means for detecting the state of the engine, the fuel injection means based on the detection result of the state detection means, controlling the fuel injection means, the fuel in the accumulator piping, and injection control means for injecting to the determined cylinder, the pressure regulating means for regulating the fuel pressure supplied from the supply pump to the accumulator pipe, at the start of the previous SL engine in the cylinder discrimination preceding stage, the supply of fuel in the by controlling the pressure regulating means to increase the fuel pressure supplied to the accumulator piping into the accumulator piping by the supply pump is most A fuel injection control apparatus for an accumulator type engine having a pressure <br/> feed control means executes the entire pumping control to be limited, a fuel pressure detecting means for detecting a fuel pressure in the accumulator piping, the state based on the detection result of the detecting means, a target fuel pressure calculation means for calculating a target fuel pressure, the cylinder discrimination stage before the start of the previous SL engine, the actual fuel pressure detected by the fuel pressure detecting means the target fuel pressure calculation means And a pumping control stopping means for stopping the pumping control by the pumping control means when the fuel pressure becomes equal to or higher than the target fuel pressure calculated by the above.

[0010] According to the second aspect of the present invention, a high pressure fuel is supplied from a supply pump, and a pressure accumulating pipe for accumulating the high pressure fuel, and a pressure accumulating pipe connected to the pressure accumulating pipe for injecting fuel into a cylinder of the engine. A fuel injection unit, a state detection unit for detecting a state of the engine, and a cylinder in which the fuel in the pressure accumulation pipe is determined by controlling the fuel injection unit based on a detection result of the state detection unit. and injection control means for injecting, the pressure regulating means for regulating the fuel pressure supplied to the accumulator pipe from the supply pump, before Symbol cylinder discrimination stage before the start of the engine, the supply to the accumulator pipe Controlling the pressure adjusting means so as to increase the fuel pressure to be supplied, and performing full-pressure feed control in which the supply of fuel to the pressure accumulating pipe by the supply pump is maximized.
A fuel injection control device for a pressure-accumulation engine, comprising: a pressure-feeding control unit that executes a fuel-pressure control unit that calculates a target fuel pressure based on a detection result of a fuel pressure in the pressure-accumulation pipe and a state detection unit. a target fuel pressure calculation means for the fuel opened by the opening operation of the own fuel opening means for reducing the fuel pressure in the accumulator piping at the cylinder discrimination stage before the start of the previous SL engine, by the fuel pressure detecting means When the detected actual fuel pressure becomes equal to or higher than the target fuel pressure calculated by the target fuel pressure calculation means, the fuel release control means opens the fuel release means and lowers the fuel pressure in the pressure accumulation pipe. The gist is that it has been established.

Further, according to the third aspect of the present invention, a high pressure fuel is supplied from a supply pump, and a pressure accumulating pipe for accumulating the high pressure fuel, and a pressure accumulating pipe connected to the pressure accumulating pipe for injecting fuel into a cylinder of the engine. A fuel injection unit, a state detection unit for detecting a state of the engine, and a cylinder in which the fuel in the pressure accumulation pipe is determined by controlling the fuel injection unit based on a detection result of the state detection unit. to the injection control means for injecting, the pressure regulating means for regulating the fuel pressure supplied to the accumulator pipe from the supply pump, before Symbol start completion stage before the start of the engine, the supply to the accumulator pipe Controlling the pressure adjusting means so as to increase the fuel pressure to be supplied, and performing full-pressure feed control in which the supply of fuel to the pressure accumulating pipe by the supply pump is maximized.
A fuel injection control device for a pressure-accumulation engine, comprising: a pressure-feeding control unit that executes a fuel-pressure control unit that calculates a target fuel pressure based on a detection result of a fuel pressure in the pressure-accumulation pipe; a target fuel pressure calculation means for, in the starting completion stage before the start of the previous SL engine, the restart time determination means for determining whether the current start is the time shortly restart operation of previous engine When the restart time determination means determines that the current start is a restart time immediately after the previous operation of the engine, the actual fuel pressure detected by the fuel pressure detection means is used to calculate the target fuel pressure. When it becomes equal to or higher than the target fuel pressure calculated by the means,
The gist of the present invention is to provide a pumping control stopping unit for stopping the pumping control by the pumping control unit.

According to the present invention, high-pressure fuel is supplied from a supply pump, and a pressure-accumulation pipe for accumulating the high-pressure fuel is connected to the pressure-accumulation pipe to inject fuel into a cylinder of the engine. The fuel injection means, the state detection means for detecting the state of the engine, and the fuel injection means are controlled based on the detection result of the state detection means to determine the fuel in the pressure accumulation pipe. and injection control means for injecting into the cylinder, and a pressure adjusting means for adjusting the fuel pressure supplied from the supply pump to the accumulator pipe, before Symbol start completion stage before the start of the engine, said accumulator piping Controlling the pressure adjusting means so as to increase the supplied fuel pressure, and performing a full pressure feed control in which the supply of fuel to the pressure accumulating pipe by the supply pump is maximized.
A fuel injection control device for a pressure-accumulation engine, comprising: a pressure-feeding control unit that executes a fuel-pressure control unit that calculates a target fuel pressure based on a detection result of a fuel pressure in the pressure-accumulation pipe; a target fuel pressure calculation means for the fuel opened by the opening operation of its own, said fuel opening means for reducing the fuel pressure in the accumulator piping at the completion of the starting stage before the start of the previous SL engine, the start of the current the previous Restart-time determining means for determining whether or not the engine has just been restarted since the start of operation of the engine; and When it is determined that there is, when the actual fuel pressure detected by the fuel pressure detecting means is equal to or higher than the target fuel pressure calculated by the target fuel pressure calculating means, the fuel opening means is opened, In that a fuel opening control means allowed to lower the fuel pressure in the serial accumulator in the pipe has as its gist.

[0013] In addition, in the invention according to claim 5, a high-pressure fuel is supplied from a supply pump, and a pressure-accumulation pipe for accumulating the high-pressure fuel; The fuel injection means, the state detection means for detecting the state of the engine, and the fuel injection means are controlled based on the detection result of the state detection means to determine the fuel in the pressure accumulation pipe. and injection control means for injecting into the cylinder, and a pressure adjusting means for adjusting the fuel pressure supplied from the supply pump to the accumulator pipe, before Symbol start completion stage before the start of the engine, said accumulator piping Controlling the pressure adjusting means so as to increase the supplied fuel pressure, and performing a full pressure feed control in which the supply of fuel to the pressure accumulating pipe by the supply pump is maximized.
A fuel injection control device for a pressure-accumulation engine, comprising: a pressure-feeding control unit that executes a fuel-pressure control unit that calculates a target fuel pressure based on a detection result of a fuel pressure in the pressure-accumulation pipe; a target fuel pressure calculation means for, in the starting completion stage before the start of the previous SL engine, this start-up, a starter for starting the engine is a just became inoperative from the operating state, the engine Restart time determining means for determining whether or not it is a restart time when the start of the engine has failed; and the restart time determining means performs the current start immediately after the starter changes from the operating state to the non-operating state. When it is determined that it is time to restart the engine when the start of the engine fails, the actual fuel pressure detected by the fuel pressure detecting means is used as the target fuel pressure calculating means. When it becomes more calculated target fuel pressure above that provided a pumping control stop means to stop the pumping control by the pumping control means it is set to its gist.

According to the present invention, a high pressure fuel is supplied from a supply pump, and a pressure accumulating pipe for accumulating the high pressure fuel, and a pressure accumulating pipe connected to the pressure accumulating pipe for injecting fuel into a cylinder of the engine. A fuel injection unit, a state detection unit for detecting a state of the engine, and a cylinder in which the fuel in the pressure accumulation pipe is determined by controlling the fuel injection unit based on a detection result of the state detection unit. to the injection control means for injecting, the pressure regulating means for regulating the fuel pressure supplied to the accumulator pipe from the supply pump, before Symbol start completion stage before the start of the engine, the supply to the accumulator pipe Controlling the pressure adjusting means so as to increase the fuel pressure to be supplied, and performing full-pressure feed control in which the supply of fuel to the pressure accumulating pipe by the supply pump is maximized.
A fuel injection control device for a pressure-accumulation engine, comprising: a pressure-feeding control unit that executes a fuel-pressure control unit that calculates a target fuel pressure based on a detection result of a fuel pressure in the pressure-accumulation pipe; a target fuel pressure calculation means for the fuel opened by the opening operation of the own fuel opening means for reducing the fuel pressure in the accumulator piping at the completion of the starting stage before the start of the previous SL engine, the current start, Immediately after the starter for starting the engine is changed from the operating state to the non-operating state, and a restart time determination unit that determines whether or not the restart is to be performed when the engine has failed to start. The restart-time determination means determines that the current start is immediately after the starter is changed from the operating state to the non-operating state, and is the restarting time when the start of the engine fails. In this case, when the actual fuel pressure detected by the fuel pressure detecting means becomes equal to or higher than the target fuel pressure calculated by the target fuel pressure calculating means, the fuel opening means is opened, and the fuel in the pressure accumulating pipe is opened. The gist of the present invention is to provide a fuel release control means for reducing the pressure.

According to a seventh aspect of the present invention, in the fuel injection control device for an accumulator type engine according to the second, fourth or sixth aspect, the fuel release means is provided between the pressure accumulation pipe and the fuel injection means. Relief valve provided in the
The gist is that the fuel injection means is constituted by at least one of a valve mechanism capable of releasing fuel during an initial invalid injection time when the fuel injection means is driven.

[0016]

(Operation) According to the first aspect of the present invention, high-pressure fuel is supplied from the supply pump to the pressure accumulating pipe, and the high-pressure fuel is accumulated in the pressure accumulating pipe. Fuel is injected into the cylinder of the engine by the fuel injection means connected to the pressure accumulation pipe. Further, the state of the engine is detected by the state detection means, and based on the detection result, the fuel injection means is controlled by the injection control means, and the fuel in the pressure accumulating pipe is
It is injected into the determined cylinder.

Further, the pressure of the fuel supplied from the supply pump to the pressure accumulating pipe is adjusted by pressure adjusting means.
Then, in the cylinder discrimination stage before the start of the engine, the pumping control means, pressure regulating means is controlled
Maximum supply of fuel to accumulator piping by supply pump
Is performed. Such pumping control, in the cylinder discrimination stage before the start of the engine, the pressure of fuel supplied to the accumulator piping is increased.

In the present invention, the fuel pressure detecting means
The fuel pressure in the pressure accumulation pipe is detected, and the target fuel pressure is calculated by the target fuel pressure calculating means based on the detection result of the state detecting means. Then, the cylinder discrimination stage before the start of the engine, when the actual fuel pressure is equal to or higher than the target fuel pressure,
The pumping control suspending means stops the pumping control by the pumping control means. Therefore, the fuel pressure in the pressure accumulation pipe does not become too high after the cylinder discrimination.

According to the second aspect of the present invention, there is provided a fuel releasing means for releasing the fuel by its own opening operation and lowering the fuel pressure in the pressure accumulating pipe. And,
In the cylinder discrimination stage before the start of the previous SL engine, when the actual fuel pressure detected becomes a target fuel pressure or more calculated by the target fuel pressure calculating means by the fuel pressure detecting means, the fuel opening control means, the fuel release means Is opened, and the fuel pressure in the pressure accumulation pipe is reduced. For this reason, similarly to the first aspect of the invention, the fuel pressure in the pressure accumulating pipe does not become too high after the cylinder discrimination. Further, the actual fuel pressure that has become equal to or higher than the target fuel pressure is reduced more quickly by the opening control.

Further, according to the third aspect of the present invention ,
In the completion of the starting stage before the start of the engine, the pumping control means, pressure regulating means is controlled supply Pont
All pumping system which the supply of fuel to the Puyoru accumulator piping is maximized
Control is executed. However, in the present invention, the time when the engine is started means a state after the ignition is turned on. Thus, after the ignition is turned on, the pressure of the fuel supplied to the pressure accumulation pipe is increased.

[0022] Now, the present invention, the completion of the starting stage before the start of the engine, whether the current start is the time shortly restart the operation of the previous engine, the restart time determining means Is determined. When it is determined by the restart time determining means that the current start is a restart time immediately after the previous operation of the engine, the actual fuel pressure detected by the fuel pressure detecting means is used as the target fuel pressure calculating means. When the fuel pressure becomes equal to or higher than the target fuel pressure calculated by the above, the pumping control by the pumping control means is stopped by the pumping control stopping means.

Here, at the time of the restart as described above, the fuel pressure in the pressure accumulating pipe is relatively high because it is shortly after the previous operation of the engine. Then, under such a relatively high fuel pressure state, since the full pressure control is performed by the pressure control means, the actual fuel pressure tends to be equal to or higher than the target fuel pressure. On the other hand, according to the present invention, under the condition that the fuel pressure tends to increase as described above, since the control is performed, the effect that the fuel pressure in the pressure accumulating pipe does not become too high, It is played more effectively.

In addition, according to the invention described in claim 4,
The actual fuel pressure detected by the fuel pressure detection means is calculated by the target fuel pressure calculation means when the restart time determination means determines that the current start is a restart time immediately after the previous operation of the engine. When the fuel pressure becomes equal to or higher than the set target fuel pressure, the fuel release control means opens the fuel release means, and the fuel pressure in the pressure accumulation pipe is reduced.
Therefore, basically the same operation as that of the third aspect is achieved. Further, the actual fuel pressure that has become equal to or higher than the target fuel pressure is reduced more quickly by the opening control.

In addition, according to the fifth aspect of the present invention ,
In the completion of the starting stage before the start of the engine, this start-up, an immediately after a starter for starting the engine becomes inoperative from the operating state, the restart in case of failure to start the engine Is determined by the restart determination means. When the restart time determination unit makes an affirmative determination and the actual fuel pressure becomes equal to or higher than the target fuel pressure, the pumping control stopping unit stops the pumping control by the pumping control unit.

[0026] In the start-up completion stage before the start of the engine, this start-up, an immediately after a starter for starting the engine becomes inoperative from the operating state, fail to start the engine In the case of the restart in the case where it has been performed, the driver performs the operation of operating the starter again. After the operation of activating the starter is performed, the pressure control means performs full pressure control for increasing the pressure in the pressure accumulating pipe, so that the fuel pressure in the pressure accumulating pipe tends to increase, and the actual fuel pressure increases. Tends to be higher than the target fuel pressure. On the other hand, according to the present invention, under the condition that the fuel pressure tends to increase as described above, since the control is performed, the effect that the fuel pressure in the pressure accumulating pipe does not become too high, It is played more effectively.

Further, according to the invention of claim 6, in the completion of the starting stage before the start of the e <br/> engine, inoperative this startup, the starter is operating state for starting the engine Immediately after the state is reached, when it is determined by the restart time determination means that the engine is restarting when the engine has failed to start, when the actual fuel pressure becomes equal to or higher than the target fuel pressure, The fuel release means is opened by the fuel release control means, and the fuel pressure in the pressure accumulation pipe is reduced. Therefore, basically the same operation as that of the fifth aspect is achieved. Further, the actual fuel pressure that has become equal to or higher than the target fuel pressure can be reduced more quickly by the opening control.

Further, according to the invention described in claim 7,
In addition to the effects of the invention described in claims 2, 4, and 6, when the actual fuel pressure becomes equal to or higher than the target fuel pressure, a relief valve provided between the pressure accumulation pipe and the fuel injection means, and the fuel At least one of the valve mechanisms provided in the injection means and capable of releasing the fuel during the initial invalid injection time when the injection means is driven is opened. For this reason, the above operation is more reliably achieved.

[0029]

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment of a fuel injection control device for a pressure-accumulation type engine according to the present invention embodied in a diesel engine will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a fuel injection control device of a pressure-accumulation type diesel engine mounted on a vehicle in the present embodiment. Diesel engine 1 is provided with a plurality of cylinders (four cylinders in the present embodiment) # 1 to # 4, and injectors constituting fuel injection means for the combustion chambers of each of cylinders # 1 to # 4. 2 are provided. Fuel injection from the injector 2 to each of the cylinders # 1 to # 4 of the diesel engine 1 is controlled by turning on / off an injection control solenoid valve 3.

The injector 2 is connected to a common rail 4 as a pressure accumulating pipe common to each cylinder. Basically, while the solenoid valve 3 for injection control is open, fuel in the common rail 4 is supplied from the injector 2. The fuel is injected into each of the cylinders # 1 to # 4. A relatively high pressure corresponding to the fuel injection pressure needs to be continuously accumulated in the common rail 4, particularly at the time of starting. Therefore, the common rail 4 is connected to the discharge port 6 a of the supply pump 6 via the supply pipe 5. In the middle of the supply pipe 5, a check valve 7 is provided. Due to the presence of the check valve 7, the supply pump 6
Supply of fuel to the common rail 4 is permitted, and
The backflow of fuel from the common rail 4 to the supply pump 6 is regulated.

The supply pump 6 has a suction port 6b
Is connected to the fuel tank 8 via a filter 9, and a filter 9 is provided in the middle of the fuel tank 8. The supply pump 6 draws fuel from the fuel tank 8 via the filter 9. At the same time, the supply pump 6 reciprocates the plunger by a cam (not shown) synchronized with the rotation of the diesel engine 1 to increase the fuel pressure to a required predetermined pressure. Then, the supply pump 6 supplies high-pressure fuel to the common rail 4.

Further, the discharge port 6 of the supply pump 6
In the vicinity of a, a pressure control valve 10 as pressure adjusting means is provided. The pressure control valve 10 is connected to the discharge port 6a
This is for controlling the fuel pressure (and, consequently, the discharge amount) discharged from the fuel cell toward the common rail 4. Pressure control valve 1
A value of 0 closes its own valve element in response to the ON signal, and permits the supply of fuel from the discharge port 6a to the common rail 4. The pressure control valve 10 opens its own valve element in response to the OFF signal, and supplies excess fuel not discharged from the discharge port 6 a from the return port 6 c provided in the supply pump 6 through the return pipe 11 to the fuel tank 8. To return to.

In this embodiment, the common rail 4 is provided with a relief valve 12, and when a predetermined condition is satisfied, the relief valve 12 is opened. As a result, the high-pressure fuel in the common rail 4 is returned to the fuel tank 8 via the return pipe 11, and the pressure in the common rail 4 is reduced.

Further, in the injector 2 according to the present embodiment, not only the fuel injection to each of the cylinders # 1 to # 4 is performed but also the solenoid valve 3 is driven by driving the solenoid valve 3 thereof. During the initial period (hereinafter referred to as “ineffective injection time”), fuel is released and the common rail 4
It has a mechanism that can reduce the fuel pressure in the interior. Here, the mechanism will be described.

As shown in FIG. 2A, the injector 2
The casing 61 is provided with a supply port 62 so that the fuel from the common rail 4 passes through a supply pipe 63 and is introduced into a lower fuel storage chamber 64 formed at a lower portion of the casing 61. I have. Further, a nozzle hole 65 that can communicate with the lower fuel storage chamber 64 is formed at the lowermost portion of the casing 61. Further, the supply port 62 is connected to an upper fuel reservoir 67 via an orifice 66. One nozzle needle 68 is slidably provided in the lower fuel storage chamber 64 and the upper fuel storage chamber 67.

The nosle needle 68 includes a tip portion 69, a large diameter portion 70, a small diameter portion 71, and a piston portion 72 in this order from the lower side. The piston portion 72 can slide vertically on a lower portion of the upper fuel storage chamber 67. A needle spring 73 is provided around the small diameter portion 71, and the urging force of the spring 73 always urges the nozzle needle 68 downward in the drawing. As a result, the tip 69 of the nozzle needle 68 is always in contact with the seat 74 near the nozzle hole 65.

The upper fuel reservoir 67 communicates with an electromagnetic valve chamber 76 via an orifice 75. The electromagnetic valve 3 includes a valve body 77, a solenoid 78, a valve body spring 79, and the like, and these are housed in an electromagnetic valve housing chamber 76. That is, the valve body 77 is provided at a lower portion of the solenoid valve housing chamber 76, and the valve body spring 79 is provided so as to abut on the ceiling of the valve body 77 and the solenoid valve housing chamber 76. Therefore, the valve body 77 is always urged downward. As a result, the orifice 75 is always closed by the biased valve body 77, and the communication between the upper fuel storage chamber 67 and the solenoid valve housing chamber 76 is shut off. When the solenoid 78 itself is excited, the valve body spring 7
This is for raising the valve body 77 upward in the drawing against the urging force of No. 9. The upper portion of the valve body 77 is formed in a flange shape, and a through hole 77a is formed in the flange portion. The casing 61 has an electromagnetic valve housing chamber 76.
A return port 80 for allowing fuel from the fuel tank to escape is formed.
From 0, surplus fuel is returned to the fuel tank 8 via the return pipe 11. The space in which the needle spring 73 is provided and the solenoid valve accommodating chamber 76 are connected by a communication passage 81. Therefore, the fuel that leaks little by little into the space where the needle spring 73 is provided flows through the communication passage 81 into the solenoid valve housing chamber 76, and then through the through hole 77 and the return port 80, and returns to the return pipe 11. It gradually flows toward.

The injector 2 constructed as described above
The operation of is described below, as shown in FIG.
First, when the solenoid 78 is not excited, the valve body 77 is urged downward by the urging force of the valve body spring 79, and the communication between the upper fuel storage chamber 67 and the electromagnetic valve housing chamber 76 is cut off. . Therefore, in such a situation, the fuel from the supply port 62 is uniformly supplied to the lower fuel storage chamber 64 and the upper fuel storage chamber 67, and the pressure balance is maintained. Accordingly, the nozzle needle 68 is provided with the needle spring 73.
The nozzle needle 68 is urged downward by the urging force of
Is maintained in contact with the seating portion 74 near the nozzle hole 65. Therefore, in this case, the fuel is not injected from the nozzle hole 65, and the fuel from the upper fuel storage chamber 67 does not quickly flow out through the return port 80. On the other hand, when the solenoid 78 is excited, the valve body 77 moves upward against the urging force of the valve body spring 79, and the upper fuel storage chamber 6
7 and the solenoid valve accommodating chamber 76 are communicated with each other. Then, for a while after that, the injector 2 behaves as shown in FIG. That is, since the valve body 77 moves upward, the fuel in the upper fuel storage chamber 67 passes through the through hole 7.
7a through return port 80 to return pipe 11
Flows to At this time, for a while after the solenoid 78 is excited, the difference between the fuel pressure in the lower fuel chamber 64 and the fuel pressure in the upper fuel chamber 67 is still smaller than the urging force of the needle spring 73. For this reason,
The nozzle needle 68 does not move and its tip 6
9 remains in contact with the seat 74. Therefore, in this state, fuel is not injected from the nozzle hole 65, and fuel from the upper fuel storage chamber 67 quickly flows out through the return port 80. This period is the invalid injection time.

Then, the fuel in the upper fuel storage chamber 67 steadily escapes, and the difference between the fuel pressure in the lower fuel storage chamber 64 and the fuel pressure in the upper fuel storage chamber 67 becomes larger than the urging force of the needle spring 73. Figure 2
As shown in (c), the nozzle needle 68 moves upward by the fuel pressure in the lower fuel storage chamber 64. This allows
The distal end portion 69 is separated from the seating portion 74, and the lower fuel storage chamber 64 and the nozzle hole 65 communicate with each other. As a result, high-pressure fuel is injected from the nozzle hole 65.

Thereafter, when the excitation of the solenoid 78 is released, the injector 2 returns to the state shown in FIG. 2A, and the fuel injection ends. That is, the solenoid 78
If the excitation time is less than the invalid injection time,
Since the state shown in FIG. 2B does not shift to the state shown in FIG. 2C, the fuel is not injected and the fuel from the upper fuel reservoir 67 only flows out quickly through the return port 80. Become.

An intake passage 13 and an exhaust passage 14 are connected to the combustion chamber of the diesel engine 1, respectively. A throttle valve (not shown) is provided in the intake passage 13, and the flow rate of intake air introduced into the combustion chamber is adjusted by opening and closing the valve.

In the combustion chamber of the diesel engine 1, a glow plug 16 is provided. The glow plug 16 is connected to the glow relay 16 immediately before the engine 1 is started.
This is a start-up assisting device that makes the device red-heat by applying a current to a, and sprays a part of the fuel spray to promote ignition and combustion.

The diesel engine 1 is provided with the following various sensors and the like for detecting the state thereof, and these constitute state detecting means in the present embodiment. That is, an accelerator sensor 21 for detecting the accelerator opening ACCP is provided near the accelerator pedal 15, and a fully-closed signal is output near the sensor 21 when the depression amount of the accelerator pedal 15 is zero. A fully closed switch 22 is provided.

An intake pressure sensor 23 is provided in the intake passage 13 via a filter 17 and a vacuum switching valve (VSV) 18. The intake pressure sensor 23 detects the intake pressure (intake pressure PM) inside the intake passage 13.

Further, the cylinder block of the diesel engine 1 is provided with a water temperature sensor 24 for detecting the temperature of the cooling water (cooling water temperature THW). In addition, the diesel engine 1 is provided with a starter 19 for starting the engine 1. The starter 19 is provided with a starter switch 25 for detecting the operation state. The starter switch 25 operates when the ignition switch (not shown) is operated from the OFF position to the start position by the driver when the diesel engine 1 is started, and the starter is operated (when the engine is in the cranking state). Signal STA
Is output as “ON”. When the start of the diesel engine 1 is completed (it becomes a complete explosion state) or the start of the engine 1 fails and the ignition switch is returned from the start position to the ON position, the starter switch 25 starts the starter switch 25. The signal STA is output as “OFF”.

In addition, the return pipe 11 is provided with a fuel temperature sensor 26 for detecting the fuel temperature THF. In addition, the common rail 4 is provided with a fuel pressure sensor 27 as fuel pressure detecting means for detecting the pressure (fuel pressure PC) of the fuel in the common rail 4.

In this embodiment, an NE sensor 28 is provided near a pulser provided on a crankshaft (not shown) of the diesel engine 1. Further, the rotation of the crankshaft is transmitted via a timing belt or the like to a camshaft (not shown) for opening and closing the intake valve 31 and the exhaust valve 32. The camshaft is set to rotate at a rotation speed of 1/2 of the crankshaft. A G sensor 29 is provided near the pulser provided on the camshaft. In the present embodiment, the engine speed NE is calculated based on the pulse signals output from the sensors 28 and 29, and the crank angle CA, the top dead center (TDC) of each of the cylinders # 1 to # 4. Is calculated (the cylinder is determined).

An intake air temperature sensor 30 for detecting an intake air temperature THA is provided near an air cleaner (not shown) at the entrance of the intake passage 13. In the present embodiment, an electronic control unit (ECU) 51 for controlling various controls of the diesel engine 1 is provided. The ECU 51 controls the injection control means, the pressure feed control means, the target fuel pressure calculation means, the pressure feed control. Stop means and the like are configured.

The electrical configuration of the ECU 51 will be described with reference to the block diagram of FIG. The ECU 51 includes a central processing controller (CPU) 52, a read-only memory (ROM) 53 in which predetermined programs and maps are stored in advance,
A random access memory (RAM) 54 for temporarily storing the operation results of the PU 52, a backup RAM 55 for storing previously stored data and the like, a timer counter 56, and the like are provided, and an input interface 57 and an output interface 58 are provided. I have. Further, the above-mentioned units 52 to 56 are connected to the input interface 57 and the output interface 58 by a bus 59.

The above-described accelerator sensor 21, intake pressure sensor 23, water temperature sensor 24, fuel temperature sensor 26, fuel pressure sensor 27, intake temperature sensor 30 and the like are each provided with a buffer, a multiplexer, and an A / D converter (all not shown). ) Is connected to the input interface 57. Also,
The NE sensor 28 and the G sensor 29 are connected to an input interface 57 via a waveform shaping circuit. Further, the fully closed switch 22 and the starter switch 25 are directly connected to the input interface 57.

The CPU 52 includes the sensors 21 to 30 described above.
Is read through the input interface 57. The solenoid valve 3, the pressure control valve 10, the relief valve 12, and the VSV 18 are connected to an output interface 58 via a drive circuit (not shown). The CPU 52 suitably controls the solenoid valve 3, the pressure control valve 10, the relief valve 12, the VSV 18 and the like based on the input values read via the input interface 58.

Next, in the present embodiment, the ECU 51
The fuel injection control among the controls executed by the ECU will be described. First, FIG. 4 is a flowchart showing one of the “main routine” executed by the ECU 51. This routine is started when the driver operates the ignition switch from the OFF position to the ON position. That is, the “main routine” is executed before the cylinder discrimination is performed.

When the processing of this routine is started, the ECU
51, first, in step 101, it is determined whether or not the current starter signal STA is “ON”. Then, when the starter signal STA is “OFF”, the subsequent processing is temporarily ended. When the starter signal STA is “ON”, in step 102, the ECU 51 determines whether or not the cylinder determination has already been completed. That is, the engine speed NE is calculated from the pulse signals output from the NE sensor 28 and the G sensor 29, and the crank angle CA, the top dead center (TD
C) is calculated, and it is determined whether the fuel injection is executable. If the determination of the cylinder has not been completed, the process proceeds to step 103.

In step 103, the ECU 51 calculates an immediate target injection amount QFINC (actually no injection is performed), and in a subsequent step 104, calculates a target fuel pressure PFIN.

In the next step 105, E
The CU 51 reads the current fuel pressure PC based on the signal from the fuel pressure sensor 27,
In, the control mode is set to the start mode. That is, the control of the pressure control valve 10 is performed in principle to increase the fuel pressure PC in the common rail 4 without performing fuel injection or the like. Thus, steps 103 to 1
In 06, even if the cylinder determination has not been completed, the calculation of the target fuel pressure PFIN and the actual fuel pressure P
C is read.

On the other hand, if it is determined in step 102 that the cylinder has already been determined, the ECU 51 determines in step 107 whether an NE pulse interrupt signal from the NE sensor 28 has been received. And NE
If there is no pulse interrupt signal, the subsequent processing is temporarily terminated. On the other hand, if there is an NE pulse interrupt signal, the ECU 51 thereafter executes a “NE interrupt routine”.

FIG. 5 shows “N” executed by the ECU 51.
9 is a flowchart showing an "E interrupt routine", which is executed every time there is an NE pulse interrupt signal, as described above. When the processing shifts to this routine, the ECU 51
In step 201, the current target injection amount Q FINC
It is determined whether or not it is the calculation timing. And when it is not the calculation timing of the target injection amount Q FINC,
Thereafter, the processing is temporarily terminated. On the other hand, if the current time is the calculation timing of the target injection amount Q FINC, the target injection amount Q FINC is calculated in step 202 based on various signals indicating the state of the diesel engine 1. At the same time, the ECU 51 determines in step 20
In step 3, the target fuel pressure PFIN is calculated, and in the following step 204, based on the signal from the fuel pressure sensor 27,
The current fuel pressure PC is read. Then, the subsequent processing ends once.

As described above, in the present embodiment, when the diesel engine 1 is started and before the cylinder discrimination is performed, the calculation of the target fuel pressure PFIN and the reading of the actual fuel pressure PC are performed in the “main routine”. After the completion of the cylinder discrimination, the calculation of the target fuel pressure PFIN and the reading of the actual fuel pressure PC are performed in the "NE interruption routine".

Next, in the present embodiment, the ECU 51
Of the control performed by the fuel pressure PC in the common rail 4 will be described. That is, FIG.
Is a flowchart showing a "pressure control valve control routine" executed by the driver. This routine is also started when the driver operates the ignition switch from the OFF position to the ON position.

When the processing shifts to this routine, the ECU
51, first, in step 301, it is determined whether or not the current engine speed NE is “0”. And
If the current engine speed NE is “0”, the process jumps to step 305 described later. On the other hand, if the current engine speed NE is not “0”, the process proceeds to step 302.

In step 302, the ECU 51
It is determined whether or not the current starter signal STA is “ON”. When the starter signal STA is “OFF”, it is determined that the diesel engine 1 has already been started, and the routine proceeds to step 303. Step 30
In 3, the ECU 51 executes the feedback control of the pressure control valve 10, and temporarily ends the subsequent processing. That is, the pressure control valve 10 is feedback-controlled so that the actual fuel pressure PC matches the target fuel pressure PFIN.

If it is determined in step 302 that the starter signal STA is "ON", the process proceeds to step 304. In step 304, the ECU 51 determines whether the cylinder determination has already been completed. And
Even when the cylinder determination has already been completed, the process proceeds to step 303 in the same manner as described above, the feedback control of the pressure control valve 10 is executed, and the ECU 51 once ends the subsequent processing.

On the other hand, if the determination of the cylinder has not been completed, or if the engine speed NE is “0”, the routine proceeds to step 305. In step 305, E
The CU 51 reads the target fuel pressure PFIN calculated in the “main routine”. Further, the following step 306
In, the ECU 51 reads the actual fuel pressure PC calculated in the “main routine”.

Further, in the next step 307, E
The CU 51 determines whether the actual fuel pressure PC exceeds the target fuel pressure PFIN. If the actual fuel pressure PC does not exceed the target fuel pressure PFIN, the control at the time of starting the pressure control valve 10 is executed in step 308 to increase the fuel pressure PC in the common rail 4 (so-called full-pressure feed control). Thereby, from the supply pump 6,
The maximum amount of fuel is pumped to the common rail 4, and the fuel pressure PC in the common rail 4 is quickly increased.

The actual fuel pressure PC is equal to the target fuel pressure PFIN.
Is exceeded, the control to turn off the pressure control valve 10 is executed in step 309 to reduce the fuel pressure PC in the common rail 4. As a result, the pressure control valve 10 opens its own valve body, and excess fuel not discharged from the discharge port 6a is returned from the return port 6c to the fuel tank 8 via the return pipe 11. Therefore, a further increase in the fuel pressure PC in the common rail 4 is suppressed, and the fuel pressure PC gradually decreases.

Next, the operation and effect of this embodiment will be described. According to the present embodiment, in the stage before the cylinder discrimination at the start of the diesel engine 1, the start control of the pressure-feed control valve 10 is executed in principle. That is, the full-pressure feed control of the fuel to the common rail 4 is performed. By the pressure feed control, the pressure (fuel pressure PC) of the fuel supplied to the common rail 4 is positively increased before the cylinder discrimination.

In this embodiment, the target fuel pressure PFIN is calculated and the actual fuel pressure PC is detected even before such a cylinder discrimination stage. When the actual fuel pressure PC exceeds the target fuel pressure PFIN, the pressure control valve 10 is turned off even before the cylinder discrimination. By this off control, the fuel pressure PC in the common rail 4 is suppressed from increasing further, and is gradually decreased. Therefore, after the cylinder discrimination, the fuel pressure PC in the common rail 4 does not become too high. As a result, it is possible to suppress generation of loud combustion noise due to excessive atomization of the fuel after the start of the diesel engine 1.

Although the NE interruption is not performed before the cylinder discrimination is completed, in the present embodiment, the calculation of the target fuel pressure PFIN and the actual The detection of the fuel pressure PC is performed. Therefore, after the ignition switch is operated to the ON position, at all times,
The target fuel pressure PFIN and the actual fuel pressure PC can be reliably grasped. As a result, the above operation and effect can be further ensured.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to the flowchart of FIG. However, since the configuration and the like of this embodiment are the same as those of the above-described first embodiment, the same members and the like are denoted by the same reference numerals and description thereof is omitted. The following description focuses on the differences from the first embodiment.

In the first embodiment, the pressure control valve 1
By controlling 0, the fuel pressure PC in the common rail 4 is controlled. On the other hand, the present embodiment is characterized in that the relief valve 12 provided on the common rail 4 is on / off controlled.

FIG. 7 is a flowchart showing a "relief valve control routine" executed by the ECU 51. In this routine, the driver operates the ignition switch from the OFF position to the ON position. It is started by doing.

When the processing shifts to this routine, the ECU
51, at step 401, determines whether or not the current engine speed NE is “0”. If the current engine speed NE is “0”, the process jumps to step 404 described below. On the other hand, if the current engine speed NE is not “0”, the routine proceeds to step 40.
Move to 2.

At step 402, the ECU 51
It is determined whether or not the current starter signal STA is “ON”. If the starter signal STA is “OFF”, it is determined that the diesel engine 1 has already been started, and in step 409, the pressure control valve 10 is fed back without performing any processing on the relief valve 12. Control, and the subsequent processing is temporarily terminated.

If it is determined in step 402 that the starter signal STA is "ON", the process proceeds to step 403. In step 403, the ECU 51 determines whether the cylinder determination has already been completed. And
Even if the cylinder determination has already been completed, step 40
In step 9, the pressure control valve 10 is feedback-controlled without performing any processing for the relief valve 12, and the subsequent processing is temporarily terminated.

On the other hand, if the determination of the cylinder has not been completed yet, or if the engine speed NE is “0”, the flow proceeds to step 404. In step 404, E
The CU 51 reads the target fuel pressure PFIN calculated in the “main routine” or the “NE interrupt routine” described in the first embodiment. In the following step 405, the ECU 51 reads the actual fuel pressure PC calculated in the "main routine" or the "NE interruption routine".

Further, in the next step 406, E
The CU 51 determines whether the actual fuel pressure PC exceeds the target fuel pressure PFIN. If the actual fuel pressure PC does not exceed the target fuel pressure PFIN, the relief valve 12 is turned off in step 407 so that the fuel pressure PC in the common rail 4 does not escape.
The startup control of the pressure control valve 10 is executed. This allows
Since the fuel in the common rail 4 is not released from the relief valve 12 and the start-up control of the pressure control valve 10 is executed separately, the fuel pressure PC in the common rail 4 is increased.

The actual fuel pressure PC is equal to the target fuel pressure PFIN.
In step 408, the relief valve 12 is controlled to the ON state. As a result, the relief valve 12 is opened, and the high-pressure fuel in the common rail 4 is returned from the relief valve 12 to the fuel tank 8 via the return pipe 11. Therefore, the fuel pressure PC in the common rail 4 decreases quickly.

As described above, also in the second embodiment, basically, the same operation and effect as in the first embodiment can be obtained. In addition, in the present embodiment, since the high-pressure fuel in the common rail 4 is released at a stretch by the on-control of the relief valve 12, the fuel pressure PC is reduced more quickly by the release control. as a result,
Even if the cylinder discrimination is completed immediately after the actual fuel pressure PC exceeds the target fuel pressure PFIN, since the fuel pressure PC decreases quickly, it is possible to more reliably suppress the generation of a large combustion noise. .

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to the flowchart of FIG. However, since the configuration of this embodiment is the same as that of the first and second embodiments described above,
The same members and the like are denoted by the same reference numerals and description thereof will be omitted. The following description focuses on the differences from the second embodiment.

In the second embodiment, the relief valve 1
2, the fuel pressure PC in the common rail 4 is controlled. On the other hand, the present embodiment is characterized in that the electromagnetic valve 3 provided in the injector 2 is controlled.

FIG. 8 is a flowchart showing an "electromagnetic valve control routine" executed by the ECU 51. In this routine, the driver operates the ignition switch from the OFF position to the ON position. It is started by doing.

When the processing shifts to this routine, the ECU
51, in steps 501 to 505,
Steps 401 to 4 of the second embodiment.
05 and step 409 (the processing corresponding to step 409 is step 508).

In the next step 506, EC
U51 determines whether or not the actual fuel pressure PC exceeds the target fuel pressure PFIN. If the actual fuel pressure PC does not exceed the target fuel pressure PFIN, it is the stage before fuel injection, and therefore, in step 509, the control at the time of starting the pressure control valve 10 is performed without particularly controlling the solenoid valve 3. Then, the subsequent processing ends once.

On the other hand, the actual fuel pressure PC is equal to the target fuel pressure P.
If the FIN is exceeded, it is determined that the fuel pressure PC in the common rail 4 needs to be reduced, and step 507 is performed.
, A so-called invalid injection control is executed [FIG.
(B)]. The invalid injection control is control for exciting the solenoid 78 for a time shorter than the invalid injection time. With this control, as described above, the fuel is not injected from the nozzle hole 65, and the fuel from the upper fuel storage chamber 67 quickly flows out through the return port 80. Therefore, as a result, common rail 4
The fuel pressure PC in the interior of the vehicle is reduced.

As described above, also in the third embodiment, basically, the same operation and effect as those of the first embodiment can be obtained. (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. However, also in this embodiment, since the configuration and the like are the same as those of the above-described first to third embodiments, the same members and the like are denoted by the same reference numerals and description thereof is omitted. The following description focuses on the differences from the above embodiments.

In each of the above embodiments, it is determined whether or not the actual fuel pressure PC exceeds the target fuel pressure PFIN before the cylinder discrimination. On the other hand, in the present embodiment, in the stage before the start of the start of the diesel engine 1, the present start is restarted shortly after the previous operation of the diesel engine 1 (hereinafter simply referred to as “restart”). "hereinafter) when the whether, and in completion of the starting stage before the start of the de I over <br/> diesel engine, this start-up, immediately after the starter 19 becomes inoperative from the operating state Accordingly, it is determined whether or not it is time to restart the diesel engine 1 when the start of the diesel engine 1 has failed (hereinafter, this is simply referred to as “restart”). If an affirmative determination is made in any of them, it is determined whether or not the actual fuel pressure PC exceeds the target fuel pressure PFIN.

Therefore, next, the processing for determining the restart or the restart of the jogging will be described in detail. That is, FIGS. 9 and 10 are flowcharts showing a “restart determination routine” for determining a restart or a choking restart performed by the ECU 51. In this routine, the driver sets the ignition switch to the OFF position. It is started by being operated from the state to the state of the ON position. FIG. 12 shows the state of the ignition switch (IG) over time and the conduction state M of the main relay [power supply for activating the ECU 51] in order to facilitate understanding of the processing contents.
6 is a timing chart showing an example of behavior of R, a starter signal STA, a water temperature THW, and the like. In the present embodiment, a restart other than the restart or the jogging restart is referred to as a “cold start” for convenience.

When the process proceeds to this routine, as shown in FIG.
It is determined whether or not the current engine speed NE is “0”. If the engine speed NE is not “0”, the process proceeds to step 612. In step 612, it is determined whether or not the starter signal STA is currently on. When the starter signal STA is on,
In step 613, the CPU restart flag XGSTO is set to "1", and in step 614, the water temperature THW at that time is set as the starting water temperature THWON and stored.

On the other hand, if the engine speed NE is "0" at step 601, the routine proceeds to step 602, where it is determined whether or not the engine is in the engine stall state. Here, the condition of being in the engine stall condition includes that the main relay MR is on and the engine speed NE is “0”. If the engine is in the engine stall state, the process proceeds to step 611 to set the restart determination flag XSTO to “1”.

If the engine is not currently in the engine stall state,
In step 603, it is determined whether or not the starter signal STA is off. If the starter signal STA is on, the process proceeds to step 613, where the restart flag XGSTO is set to "1", and in step 614, the water temperature THW at that time is set as the starting water temperature THWON. ,Remember. That is, when at least the starter signal STA is turned on, the restart delay determination flag XGSTO is set to “1”.

Further, when the starter signal STA is turned off in step 603, it is determined in step 604 whether or not the churn restart determination flag XGSTO is currently set to "1". If the restart judgment flag XGSTO is not currently set to “1”, the process jumps to step 606. On the other hand, the restart judgment flag XGST
If O is set to “1”, step 605
Move to.

At step 605, it is determined whether or not the restart of the choongake is being executed. That is, whether or not a value obtained by subtracting the currently stored starting water temperature THWON from the IG-off water temperature learning value GTHWIOF learned when the ignition switch is turned off exceeds a predetermined value α. Is determined. If a negative determination is made in step 605, the water temperature when the starter 19 is turned on (start-up water temperature THWON) has hardly decreased with respect to the IG-off water temperature learning value GTHWIOF. It is determined that the start is a so-called restart of the jingle. In such a case, the ECU 51 shifts the processing to step 617. On the other hand, if an affirmative determination is made in step 605, the IG-off water temperature learning value GT
The water temperature when the starter 19 is turned on (the starting water temperature THWON) is lower than the HWIOF, and the process proceeds to step 606 on the assumption that the current start is not a so-called restart.

In steps 606 to 611, 615, and 616, it is determined whether or not a so-called restart is performed. That is, in step 606, the ECU 51 determines whether or not the fuel temperature THF detected by the fuel temperature sensor 26 is substantially equal to the intake air temperature THA detected by the intake air temperature sensor 30. If the fuel temperature THF and the intake air temperature THA are completely different values, the process jumps to step 609.

On the other hand, if the fuel temperature THF and the intake air temperature THA are almost equal, in step 607, the ECU 51 determines whether or not the current fuel temperature THF is higher than the minimum coolant temperature learning value GTHWMN. to decide. Here, the minimum water temperature learning value GTHWMN is the cooling water temperature THW.
Is the lowest value up to that point, and is learned and updated each time the value falls below the lowest value. Then, when the current fuel temperature THF is not higher than the minimum coolant temperature learning value GTHWMN, the process jumps to step 609.

On the other hand, if the current fuel temperature THF is higher than the minimum coolant temperature learning value GTHWMN, in step 608, the current fuel temperature THF is set as the minimum coolant temperature learning value GTHWMN and updated. This is, for example, when the minimum water temperature learning value GTHWMN of the previous day was “0 ° C.”, and when the current fuel temperature THF is “5 ° C.”, that value is newly adopted as the minimum water temperature learning value GTHWMN. It is the purpose.

Further, steps 606 and 607
Alternatively, the process proceeds from step 608, and in step 609, the currently set minimum water temperature learning value GTHWM.
It is determined whether or not N is lower than the current cooling water temperature THW. Then, the currently set minimum water temperature learning value GTH
If WMN is not lower than the current coolant temperature THW, in step 615, the current coolant temperature THW is set as the minimum coolant temperature learning value GTHWMN. further,
In the following step 616, it is determined that the vehicle is currently under the so-called cold start condition, and the restart determination flag XS
TO is set to "0", and the routine goes to Step 617.

On the other hand, if it is determined in step 609 that the currently set minimum coolant temperature learning value GTHWMN is lower than the current coolant temperature THW, the process proceeds to step 610. In step 610, the ECU 51 determines whether a value obtained by subtracting the currently set minimum coolant temperature learning value GTHWMN from the current coolant temperature THW is greater than the reference value MTHW. Here, the reference value MTHW is, as shown in FIG. 11, the IG-off water temperature learning value GTH.
This value is determined by referring to a map for a value obtained by subtracting the minimum water temperature learning value GTHWMN from WIOF. That is, the reference value MTHW is set to a larger value as the value obtained by subtracting the minimum water temperature learning value GTHWMN from the IG-off water temperature learning value GTHWIOF is larger. this is,
This takes into account the fact that there is a difference in the manner in which the water temperature drops between the case where the ignition switch is turned off in a state where the water temperature is relatively low and the case where the ignition switch is turned off in a state where the water temperature is relatively high. Then, if the value obtained by subtracting the currently set minimum coolant temperature learning value GTHWMN from the current coolant temperature THW is not greater than the reference value MTHW, in step 616, the ECU 51 proceeds to step 616 under the so-called cold start condition. The restart determination flag X
The STO is set to “0”, and the process proceeds to step 617.

If the value obtained by subtracting the currently set minimum water temperature learning value GTHWMN from the current cooling water temperature THW is larger than the reference value MTHW, step 6 is executed.
Move to 11. In step 611, the ECU 51
Determines that the vehicle is currently under so-called restart conditions, sets the restart determination flag XSTO to "1", and proceeds to step 617.

As described above, steps 601 to 6
In step 16, it is determined whether or not the present time is the so-called restart of the choke, and if it is determined that the present time is not the restart of the choke, it is determined whether the restart is the cold start or the restart.

Now, steps 605, 611,
Step 612, step 614, or step 616
In step 617, it is determined whether or not the ignition switch is currently in the ON state as shown in FIG. Then, if the ignition switch is currently in the ON state, the subsequent processing is temporarily terminated. On the other hand, if the ignition switch is currently in the off state, the process proceeds to step 618.

In step 618, it is determined whether or not main relay MR is currently on. And
When the main relay MR is currently in the off state, it is determined that a considerable time has elapsed since the operation of the diesel engine 1 was stopped, and the subsequent processing is temporarily terminated. Also, when the main relay MR is currently in the ON state, not much time has elapsed since the ignition switch was switched from the ON state to the OFF state, and the processing when the ignition switch was subsequently switched OFF is performed. The process proceeds to step 619 to perform the process.

In step 619, the ECU 51 determines
IG-off water temperature learning value GTHW based on the current cooling water temperature THW
Set and store as IOF. Also, the following step 6
In 20, the ECU 51 determines whether or not the restart delay determination flag XGSTO is currently set to “1”. Then, the restart judgment flag XG
If the STO is “0”, the subsequent processing is temporarily terminated without performing any processing. On the other hand, if the restart flag XGSTO is “1”, the process proceeds to step 621 to determine whether it is appropriate to hold the flag at “1”.

In step 621, the ECU 51 determines
From the starting cooling water temperature THWSON, the IG set this time
It is determined whether the value obtained by subtracting the off-time water temperature learning value GTHWIOF is smaller than a predetermined value β. Then, when the value obtained by subtracting the IG-off water temperature learning value GTHWIOF from the starting-time cooling water temperature THWSON is smaller than a predetermined value β, the restart delay determination flag XGSTO.
It is appropriate to hold “1” as “1”, and the subsequent processing is temporarily terminated without performing any processing. On the other hand, if the value obtained by subtracting the IG-off water temperature learning value GTHWIOF from the starting-time cooling water temperature THWSON is equal to or greater than a predetermined value β, it is not appropriate to hold the jungage restart determination flag XGSTO at “1”. , To 622.

Then, at step 622, the ECU
In step 51, the restart flag XGSTO is set to "0", and the subsequent processing is temporarily terminated. As described above, in steps 617 to 622, the processing when the ignition switch is turned off is executed.

In the present embodiment, the control of the fuel pressure PC in the common rail 4 is performed based on the restart determination flag XGSTO and the restart determination flag XSTO set as described above. Next, the control contents will be described.

FIG. 13 is a flowchart showing a "relief valve control routine" executed by the ECU 51. In this routine also, the driver operates the ignition switch from the OFF position to the ON position. It is started by doing.

When the processing shifts to this routine, the ECU
51 determines in step 701 whether or not the restart determination flag XSTO is currently set to “1”. When the restart determination flag XSTO is set to “1”, the control of the fuel pressure PC in the common rail 4 according to the present embodiment is performed in step 703.
Move to. Also, the restart determination flag XSTO is "0".
If it is set to, the process proceeds to step 702.

In step 702, it is determined whether or not the restart judgment flag XGSTO is currently set to "1". Then, also when the restart judgment flag XGSTO is set to “1”,
The process proceeds to step 703 to execute the control of the fuel pressure PC in the common rail 4 according to the present embodiment. If the restart flag XGSTO is set to "0", the feedback control of the pressure control valve 10 is executed in step 710, and the subsequent processing is temporarily terminated.

Now, step 701 or step 702
In step 703, it is determined whether the current engine speed NE is "0". If the current engine speed NE is “0”, the process jumps to step 705 described later. On the other hand, if the current engine speed NE is not “0”, the process proceeds to step 704.

At step 704, the ECU 51 determines
It is determined whether or not the current starter signal STA is “ON”. When the starter signal STA is “OFF”, it is determined that the diesel engine 1 has already been started, and the subsequent processing is temporarily terminated without performing any processing on the relief valve 12.

If it is determined in step 704 that the starter signal STA is “ON”, the process proceeds to step 700. In step 700, it is determined whether or not the cylinder determination has been completed. If the cylinder discrimination has been completed, at step 710, the pressure control valve 1
0 feedback control is performed, and the subsequent processing is temporarily terminated. If the cylinder discrimination has not been completed, the process proceeds to step 705.

At step 705, the ECU 51
The target fuel pressure PFIN calculated in the “main routine” described in the first embodiment is read. In the following step 706, the ECU 51 reads the actual fuel pressure PC calculated in the “main routine”.

Further, in the next step 707, E
The CU 51 determines whether the actual fuel pressure PC exceeds the target fuel pressure PFIN. If the actual fuel pressure PC does not exceed the target fuel pressure PFIN, the relief valve 12 is turned off in step 708 so that the fuel pressure PC in the common rail 4 is not escaped.
The startup control of the pressure control valve 10 is executed. This allows
Since the fuel in the common rail 4 is not released from the relief valve 12 and the control at the time of starting the pressure control valve 10 is performed, the fuel pressure PC in the common rail 4 is increased.

Further, the actual fuel pressure PC is equal to the target fuel pressure PFIN.
Is exceeded, in step 709, the relief valve 12 is controlled to the ON state. As a result, the relief valve 12 is opened, and the high-pressure fuel in the common rail 4 is returned from the relief valve 12 to the fuel tank 8 via the return pipe 11. Therefore, the fuel pressure PC in the common rail 4 decreases quickly.

As described above, also in the present embodiment, the high-pressure fuel in the common rail 4 is released at a stretch by the ON control of the relief valve 12, so that the fuel pressure PC is reduced more quickly by the release control. as a result,
Even if the cylinder discrimination is completed immediately after the actual fuel pressure PC exceeds the target fuel pressure PFIN, since the fuel pressure PC decreases quickly, it is possible to more reliably suppress the generation of a large combustion noise. .

Also, in the present embodiment, unlike the first to third embodiments in which it is determined whether or not the cylinder discrimination has been completed, when it is determined that the engine is to be restarted, or , If it is determined that it is a restart
The comparison between the actual fuel pressure PC and the target fuel pressure PFIN is executed. Here, at the time of the restart as described above, the fuel pressure PC in the common rail 4 is relatively high because it is shortly after the previous operation of the diesel engine 1. Then, under such a relatively high fuel pressure state, since the pressure feed control by the supply pump 6 is performed, the actual fuel pressure PC tends to be equal to or higher than the target fuel pressure PFIN.

Further, at the time of restarting the jogging, the driver performs the operation of operating the starter 19 again. After the operation for operating the starter 19 is performed, the pressure feed control by the supply pump 6 is performed to increase the fuel pressure PC in the common rail 4, and the actual fuel pressure P
C is more likely to be higher than the target fuel pressure PFIN.

On the other hand, according to the present embodiment, the above-described control is performed under the condition that the fuel pressure PC tends to increase as described above.
Has the effect of not being too high,
It is played more effectively.

Further, in the present embodiment, when determining whether or not to restart, not only the cooling water temperature THW but also the intake air temperature T
The HA and the fuel temperature THF are also taken into consideration (steps 606 to 610, step 615). For this reason, even if any of the sensors 24, 26, and 30 has failed, it is possible to ensure the determination as to whether or not to restart.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIGS. However, also in this embodiment, since the configuration and the like are the same as those of the above-described first to fourth embodiments, the same members and the like are denoted by the same reference numerals and description thereof is omitted. The following description focuses on the differences from the above embodiments.

In the fourth embodiment, at the stage before the start of the start of the diesel engine 1, it is determined whether or not the restart is being performed and whether or not the restart is to be performed. Then, when an affirmative determination is made in any of the cases, it is determined whether or not the actual fuel pressure PC exceeds the target fuel pressure PFIN. The point that these determinations are made is common to the present embodiment. However, the present embodiment is different from the fourth embodiment in the method of determining whether or not it is at the time of restarting and whether or not it is at the time of restarting choongake.

Therefore, next, the processing for determining the restart or the restart of the jogging will be described in detail. That is, FIGS. 14 and 15 are flowcharts showing a “restart determination routine” for determining the restart or the choking restart performed by the ECU 51, and this routine is also performed when the ignition switch is turned off by the driver. It is started by being operated from the state to the state of the ON position. FIG. 16 shows the state of the ignition switch (IG) with respect to the passage of time and the conduction state M of the main relay [power supply for activating the ECU 51] in order to facilitate understanding of the processing contents.
6 is a timing chart showing an example of behavior of R, a starter signal STA, a water temperature THW, and the like. Also in the present embodiment, a restart other than the restart or the jog-gag restart will be referred to as “cold start” for convenience.

When the process proceeds to this routine, as shown in FIG.
It is determined whether or not the current engine speed NE is “0”. If the engine speed NE is not “0”, the process proceeds to step 809. In step 809, it is determined whether or not the starter signal STA is currently on. When the starter signal STA is on,
In step 810, the restart flag XGSTO is set to "1", and in the following step 811, the water temperature THW at that time is set as a starter-on water temperature learning value GTHWSON and stored.

On the other hand, if the engine speed NE is "0" at step 801, the routine proceeds to step 802, where it is determined whether or not the engine is in the engine stall state. If it is currently in the engine stall state, step 808
Then, the restart determination flag XSTO is set to "1".

When the engine is not currently in the engine stall state,
In step 803, it is determined whether the starter signal STA is off. If the starter signal STA is on, the process proceeds to step 810, in which the restart flag XGSTO is set to "1". In step 811, the water temperature THW at that time is set to a starter-on learning temperature GTHWSON. Set as and memorize. That is, when at least the starter signal STA is turned on, the restart delay determination flag XGSTO is set to “1”.

Further, if the starter signal STA is off at step 803, it is determined at step 804 whether or not the restart delay determination flag XGSTO is currently set to "1". If the restart judgment flag XGSTO is not currently set to "1", the process jumps to step 806. On the other hand, the restart judgment flag XGST
If O is set to “1”, step 805
Move to.

At step 805, it is determined whether or not the restart of the choongake is currently being executed. That is, the starter-on water temperature learning value GTHWSON
Then, it is determined whether or not the value obtained by subtracting the current cooling water temperature THW exceeds a predetermined value α (however, α may be a value different from that of the fourth embodiment). If a negative determination is made in step 805,
For the water temperature learning value GTHWSONIG at starter on,
Since the current cooling water temperature THW has hardly decreased, it is determined that the current start is a so-called restart of the jingle. In such a case, the ECU 51 shifts the processing to step 813. On the other hand, step 80
If an affirmative determination is made in step 5, it is determined that the current start is not a so-called restart, and step 8
Shift to 06.

In steps 806 to 808 and step 812, it is determined whether or not a so-called restart is performed. That is, in step 806, the ECU 51
Determines whether the IG-off water temperature learning value GTHWIOF is lower than the current cooling water temperature THW. And IG
The OFF coolant temperature learning value GTHWIOF is equal to the current coolant temperature TH.
If it is equal to or greater than W, it is determined that the vehicle is currently under a so-called cold start condition, and the restart determination flag XSTO is set to “0”.
And the process proceeds to step 813.

On the other hand, in step 806, I
When the G-off water temperature learning value GTHWIOF is equal to the current cooling water temperature T
If it is lower than HW, the process proceeds to step 807.
In step 807, the ECU 51 determines whether or not a value obtained by subtracting the current cooling water temperature THW from the IG-off water temperature learning value GTHWIOF is smaller than the reference value MTHW. Here, the reference value MTHW is, as shown in parentheses in FIG. 11, the IG-off water temperature learning value GTHWIOF.
Is a value determined by referring to the map. That is, the reference value MTHW is set to a larger value as the IG-off water temperature learning value GTHWIOF is larger.
This takes into account the fact that there is a difference in the manner in which the temperature of the ignition switch is turned off when the water temperature is relatively low and when the ignition switch is turned off when the water temperature is relatively high. If the value obtained by subtracting the current cooling water temperature THW from the IG-off water temperature learning value GTHWIOF is not smaller than the reference value MTHW, in step 812, the ECU 51 determines that the current condition is under so-called cold start conditions. The restart determination flag XS
TO is set to "0", and the routine goes to Step 813.

The IG-off water temperature learning value GTHWIO
The value obtained by subtracting the current cooling water temperature THW from F is a reference value M
If it is smaller than THW, the process proceeds to step 808. In step 808, the ECU 51 determines that the vehicle is currently under the restart condition, sets the restart determination flag XSTO to “1”, and proceeds to step 813.

As described above, steps 801 to 8
In 12, it is determined whether or not the current time is a so-called restart of the choke, and if it is determined that the present time is not the restart of the choke, it is determined whether it is the cold start or the restart.

Now, steps 805, 811,
In step 813 after shifting from step 808 or step 812, as shown in FIG. 15, it is determined whether or not the ignition switch is currently on.
Then, if the ignition switch is currently in the ON state, the subsequent processing is temporarily terminated. In contrast,
If the ignition switch is currently off, the process proceeds to step 814.

In step 814, it is determined whether or not main relay MR is currently on. And
When the main relay MR is currently in the off state, it is determined that a considerable time has elapsed since the operation of the diesel engine 1 was stopped, and the subsequent processing is temporarily terminated. Also, when the main relay MR is currently in the ON state, not much time has elapsed since the ignition switch was switched from the ON state to the OFF state, and the processing when the ignition switch was subsequently switched OFF is performed. The process proceeds to step 815 to perform the process.

At step 815, the ECU 51 sets
The current cooling water temperature THW is set as the IG-off water temperature THWIOF and stored. Further, in the following step 816, the ECU 51 determines whether or not the churn restart determination flag XGSTO is currently set to “1”. Then, when the restart judgment flag XGSTO is “0”, the subsequent processing is temporarily terminated without performing any processing. On the other hand, if the restart flag XGSTO is “1”, the process proceeds to step 817 to determine whether it is appropriate to hold the flag at “1”.

At step 817, the ECU 51 sets
A value obtained by subtracting the currently set IG-off water temperature THWIOF from the starter-on water temperature learning value GTHWSONIG is smaller than a predetermined value β (β may be a different value from the fourth embodiment). It is determined whether or not.
Then, the starter-on water temperature learning value GTHWSONIG
If the value obtained by subtracting the IG-off water temperature THWIOF from the above is smaller than a predetermined value β, it is determined that it is appropriate to hold the choongake restart determination flag XGSTO at “1”, and any processing is performed. Thereafter, the subsequent processing is temporarily terminated. On the other hand, the water temperature learning value GTHW at starter on
If the value obtained by subtracting the water temperature THWIOF at the time of IG off from SONIG is equal to or more than the predetermined value β, it is determined that it is not appropriate to hold the jungage restart determination flag XGSTO at “1”, and the process proceeds to step 818.

Then, at step 818, the ECU
51 sets the cooling water temperature THW at that time as the IG-off water temperature learning value GTHWIOF, and, in the next step 819, the choongake restart determination flag X
Set GSTO to "0". Then, the ECU 51 once ends the subsequent processing. Thus, step 81
In steps 3 to 819, processing is performed when the ignition switch is turned off.

[0139] Even if such a determination method is adopted, the same operational effects as those of the fourth embodiment can be obtained. It should be noted that the present invention is not limited to the above embodiments, and may be implemented as follows, with a part of the configuration appropriately changed without departing from the spirit of the invention.

(1) Instead of the judging restart judging method in the third and fourth embodiments, for example, the following judging method may be used. That is, FIG.
It is a flowchart which shows the "Jungage restart determination routine" performed by the CU 51.
The operation is started when the driver operates the ignition switch from the OFF position to the ON position.

When the processing shifts to this routine, the ECU
51 determines in step 901 whether or not the current engine speed NE is “0”. If the engine speed NE is not "0", the routine proceeds to step 90.
Move to 6. In step 906, it is determined whether or not the starter signal STA is currently ON. If the starter signal STA is on, the CPU proceeds to step 907 to set the singing restart restart flag XGSTO to “1”.
, And the process proceeds to step 908.

On the other hand, if the engine speed NE is "0" at step 901, the routine proceeds to step 902, where it is determined whether or not the engine is currently in the engine stall state. If it is currently in the engine stall state, step 908
Move to

If the engine is not currently in the engine stall state,
In step 903, it is determined whether or not the current coolant temperature THW is substantially equal to the current fuel temperature THF. If the cooling water temperature THW is not substantially equal to the fuel temperature THF, the process proceeds to step 908. If the cooling water temperature THW is substantially equal to the fuel temperature THF, the process proceeds to step 904.

In step 904, it is determined whether or not the current cooling water temperature THW is substantially equal to the current intake air temperature THA. Then, the cooling water temperature THW becomes equal to the intake air temperature TH.
If it is not substantially equal to A, the process proceeds to step 908. If the cooling water temperature THW is substantially equal to the intake air temperature THA, the process proceeds to step 905.

At step 905, the ECU 51
It is determined whether or not starter signal STA is off. If the starter signal STA is on, the flow shifts to step 907, where the restart determination flag XGST is set.
O is set to "1", and the routine goes to Step 908.

If it is determined in step 905 that the starter signal STA is off, it is determined in step 908 whether the ignition switch is currently on. Then, if the ignition switch is currently in the ON state, the subsequent processing is temporarily terminated. On the other hand, if the ignition switch is currently in the off state, the process proceeds to step 909.

In step 909, it is determined whether or not the main relay MR is currently on. And
When the main relay MR is currently in the off state, it is determined that a considerable time has elapsed since the operation of the diesel engine 1 was stopped, and the subsequent processing is temporarily terminated. Also, when the main relay MR is currently in the ON state, not much time has elapsed since the ignition switch was switched from the ON state to the OFF state, and the processing when the ignition switch was subsequently switched OFF is performed. The process proceeds to step 910 to perform the process.

In step 910, the ECU 51
It is determined whether or not the current coolant temperature THW is substantially equal to the current fuel temperature THF. If not, the subsequent processing is temporarily terminated. If the cooling water temperature THW is substantially equal to the fuel temperature THF, the process proceeds to step 911.

In step 911, it is determined whether or not the current cooling water temperature THW is substantially equal to the current intake air temperature THA. If not, the subsequent processing is temporarily terminated. If the cooling water temperature THW is substantially equal to the intake air temperature THA, the process proceeds to step 912.

Then, at step 912, the restart flag XGSTO is set to "0".
Thereafter, the processing is temporarily terminated. As described above, when judging whether or not restarting is possible, the judging method as described above may be employed.

(2) In the first embodiment,
At the stage before the cylinder discrimination, the fuel pressure PC is detected in the “main routine”, and the target fuel pressure PFIN is calculated.
After the cylinder discrimination, the "NE interruption routine" detects the fuel pressure PC,
The target fuel pressure PFIN was calculated. In contrast,
In the main routine, the time is divided into a time interruption or an NE interruption. Before the cylinder discrimination, the fuel pressure PC is detected by the “time interruption routine”, the target fuel pressure PFIN is calculated, and after the cylinder discrimination, the “NE interruption” is performed. Routine "fuel pressure PC
May be detected to calculate the target fuel pressure PFIN .

(3) In the fourth embodiment, the case where the fuel pressure PC is controlled by controlling the relief valve 12 has been embodied. However, in the first embodiment and the third embodiment, the fuel pressure PC is controlled. As described above, the fuel pressure PC may be controlled by controlling the pressure control valve 10 and the electric valve 3.

(4) In the first and third embodiments, the relief valve 12 may be omitted. With such a configuration, cost can be reduced.

(5) In the first and second embodiments, a normal injector without the solenoid valve 3 may be used. (6) In the above embodiment, the present invention is embodied in the diesel engine 1. However, the present invention is not limited to the diesel engine 1, but can be embodied in a gasoline engine.

[0155]

As described in detail above, according to the present invention,
In a fuel injection control device for a pressure-accumulation type engine, when starting the engine, full-pressure feed control that maximizes the supply of fuel to a pressure-accumulation pipe by a supply pump is executed.
Thus, there is an excellent effect that generation of loud combustion noise due to too high a fuel pressure in the pressure accumulating pipe can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a fuel injection control device of a pressure-accumulation engine according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an injector, wherein (a)
FIG. 3 is a cross-sectional view showing a state in which the solenoid is not excited, FIG. 3B is a sectional view showing an invalid injection state, and FIG.

FIG. 3 is a block diagram showing an electrical configuration of an ECU.

FIG. 4 is a flowchart showing a “main routine” executed by the ECU.

FIG. 5 is an “NE interruption routine” executed by the ECU;
5 is a flowchart showing the process.

FIG. 6 is a flowchart showing a “pressure control valve control routine” executed by the ECU.

FIG. 7 is a flowchart illustrating a “relief valve control routine” executed by an ECU according to the second embodiment.

FIG. 8 is a flowchart illustrating an “electromagnetic valve control routine” executed by an ECU according to the third embodiment.

FIG. 9 is a flowchart illustrating a “restart determination routine” executed by the ECU according to the fourth embodiment;

FIG. 10 is a flowchart showing a continuation of the “restart determination routine” of FIG. 9;

FIG. 11 is a map showing a relationship between a reference value and a value obtained by subtracting a minimum water temperature learning value from an IG off water temperature learning value (or a IG off water temperature learning value).

FIG. 12 is a diagram showing a state of an ignition switch over time, a state of conduction of a main relay, a starter signal, a restart determination flag, a restart determination flag, 5 is a timing chart showing an example of behavior such as an engine speed and a water temperature.

FIG. 13 is a flowchart showing a “relief valve control routine” executed by the ECU.

FIG. 14 is a flowchart illustrating a “restart determination routine” executed by the ECU according to the fifth embodiment.

FIG. 15 is a flowchart showing a continuation of the “restart determination routine” of FIG. 14;

FIG. 16 shows the state of the ignition switch with respect to the passage of time, the conduction state of the main relay, the starter signal, the restart determination flag, the restart determination flag, and the like, in order to facilitate understanding of the processing content of the “restart determination routine”. 5 is a timing chart showing an example of behavior such as an engine speed and a water temperature.

FIG. 17 is a flowchart showing a “Jongage restart determination routine” executed by the ECU in another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Diesel engine, 2 ... Injector which comprises fuel injection means, 3 ... Solenoid valve as fuel release means, 4 ...
Common rail as accumulator pipe, 5 supply pipe, 6 supply pump, 10 pressure control valve as pressure adjusting means, 11 return pipe, 12 relief valve as fuel release means, 21 accelerator as state detecting means Sensor, 22 ... Fully-closed switch as state detecting means, 23 ...
Intake pressure sensor as state detecting means, 24 ... water temperature sensor as state detecting means, 25 ... starter switch as state detecting means, 26 ... fuel temperature sensor as state detecting means, 27 ... fuel pressure detecting means, state detecting means , Fuel pressure sensor, 28 ... NE sensor as state detecting means, 29 ...
G sensor as state detection means, 30 ... intake air temperature sensor as state detection means, 51 ... injection control means, pressure feed control means, target fuel pressure calculation means, pressure feed control stop means, fuel release control means, restart time determination means, etc. An electronic control unit (ECU) constituting the electronic control unit.

Continuation of the front page (56) References JP-A-6-207548 (JP, A) JP-A-2-146256 (JP, A) JP-A-5-231179 (JP, A) JP-A-5-149168 (JP) , A) JP-A-4-339152 (JP, A) JP-A-59-211172 (JP, A) JP-A-8-291729 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) F02D 41/00-41/40 F02M 37/00 F02M 47/02 F02M 59/20

Claims (7)

(57) [Claims] 1. A high pressure fuel is supplied from a supply pump, and a pressure accumulating pipe for accumulating the high pressure fuel, a fuel injection means connected to the pressure accumulating pipe for injecting fuel into a cylinder of the engine, and a state of the engine State detection means for detecting the fuel injection means, based on the detection result of the state detection means, to inject the fuel in the pressure accumulation pipe to the determined cylinder; and pressure regulating means for regulating the fuel pressure supplied from the supply pump to the accumulator piping, in the cylinder discrimination stage before the start of the previous SL engine, the pressure to increase the fuel pressure supplied to the accumulator pipe Controlling the adjusting means to execute a full-pressure feed control in which the supply of fuel to the pressure accumulation pipe by the supply pump is maximized.
A fuel injection control apparatus for an accumulator type engine having a pumping control means that, a fuel pressure detecting means for detecting a fuel pressure in the accumulator piping, based on the detection result of the state detecting means, calculates a target fuel pressure a target fuel pressure calculation means, the cylinder discrimination stage before the start of the previous SL engine, when the actual fuel pressure detected becomes a target fuel pressure or more calculated by the target fuel pressure calculating means by said fuel pressure detecting means, wherein A fuel injection control device for a pressure-accumulation type engine, comprising: a pumping control stopping unit for stopping the pumping control by the pumping control unit. 2. A high pressure fuel is supplied from a supply pump, and a pressure accumulating pipe for accumulating the high pressure fuel, a fuel injection means connected to the pressure accumulating pipe for injecting fuel into a cylinder of the engine, and a state of the engine State detection means for detecting the fuel injection means, based on the detection result of the state detection means, to inject the fuel in the pressure accumulation pipe to the determined cylinder; and pressure regulating means for regulating the fuel pressure supplied from the supply pump to the accumulator piping, in the cylinder discrimination stage before the start of the previous SL engine, the pressure to increase the fuel pressure supplied to the accumulator pipe Controlling the adjusting means to execute a full-pressure feed control in which the supply of fuel to the pressure accumulation pipe by the supply pump is maximized.
A fuel injection control apparatus for an accumulator type engine having a pumping control means that, a fuel pressure detecting means for detecting a fuel pressure in the accumulator piping, based on the detection result of the state detecting means, calculates a target fuel pressure a target fuel pressure calculating means, the fuel opened by an opening operation of the own fuel opening means for reducing the fuel pressure in the accumulator piping at the cylinder discrimination stage before the start of the previous SL engine, detected by said fuel pressure detecting means Fuel release control means for opening the fuel release means and reducing the fuel pressure in the accumulator pipe when the actual fuel pressure obtained is equal to or higher than the target fuel pressure calculated by the target fuel pressure calculation means. A fuel injection control device for a pressure accumulating engine. 3. A pressure-accumulation pipe for supplying high-pressure fuel from a supply pump and accumulating the high-pressure fuel; fuel-injection means connected to the pressure-accumulation pipe for injecting fuel into a cylinder of the engine; State detection means for detecting the fuel injection means, based on the detection result of the state detection means, to inject the fuel in the pressure accumulation pipe to the determined cylinder; and pressure regulating means for regulating the fuel pressure supplied from the supply pump to the accumulator piping, in the start-up completion stage before the start of the previous SL engine, the pressure to increase the fuel pressure supplied to the accumulator pipe Controlling the adjusting means to execute a full-pressure feed control in which the supply of fuel to the pressure accumulation pipe by the supply pump is maximized.
A fuel injection control apparatus for an accumulator type engine having a pumping control means that, a fuel pressure detecting means for detecting a fuel pressure in the accumulator piping, based on the detection result of the state detecting means, calculates a target fuel pressure a target fuel pressure calculation means, the start-up completion stage before the start of the previous SL engine, and whether restart time determining means for determining whether the current start is the time shortly restart operation of previous engine, The actual fuel pressure detected by the fuel pressure detecting means is used as the target fuel pressure calculating means when the restart time determining means determines that the current start is a restart just after the previous operation of the engine. And a pressure-feeding control stopping means for stopping the pressure-feeding control by the pressure-feeding control means when the fuel pressure becomes equal to or higher than the target fuel pressure calculated by (1). 4. A high pressure fuel is supplied from a supply pump, and a pressure accumulating pipe for accumulating the high pressure fuel, a fuel injection means connected to the pressure accumulating pipe for injecting fuel into a cylinder of the engine, and a state of the engine State detection means for detecting the fuel injection means, based on the detection result of the state detection means, to inject the fuel in the pressure accumulation pipe to the determined cylinder; and pressure regulating means for regulating the fuel pressure supplied from the supply pump to the accumulator piping, in the start-up completion stage before the start of the previous SL engine, the pressure to increase the fuel pressure supplied to the accumulator pipe Controlling the adjusting means to execute a full-pressure feed control in which the supply of fuel to the pressure accumulation pipe by the supply pump is maximized.
A fuel injection control apparatus for an accumulator type engine having a pumping control means that, a fuel pressure detecting means for detecting a fuel pressure in the accumulator piping, based on the detection result of the state detecting means, calculates a target fuel pressure a target fuel pressure calculating means, the fuel opened by an opening operation of the own fuel opening means for reducing the fuel pressure in the accumulator piping, before Symbol start completion stage before the start of the engine, this start-up of the previous Restart-time determining means for determining whether or not the engine has just been restarted; and the restart-time determining means determines that the current start is a restart immediately after the previous operation of the engine. When it is determined that the actual fuel pressure detected by the fuel pressure detecting means is equal to or higher than the target fuel pressure calculated by the target fuel pressure calculating means, the fuel opening means is opened, A fuel injection control device for a pressure-accumulation type engine, comprising: fuel release control means for reducing fuel pressure in a pressure accumulation pipe. 5. A pressure-accumulation pipe for supplying high-pressure fuel from a supply pump to accumulate the high-pressure fuel, a fuel injection means connected to the pressure-accumulation pipe for injecting fuel into a cylinder of the engine, and a state of the engine. State detection means for detecting the fuel injection means, based on the detection result of the state detection means, to inject the fuel in the pressure accumulation pipe to the determined cylinder; and pressure regulating means for regulating the fuel pressure supplied from the supply pump to the accumulator piping, in the start-up completion stage before the start of the previous SL engine, the pressure to increase the fuel pressure supplied to the accumulator pipe Controlling the adjusting means to execute a full-pressure feed control in which the supply of fuel to the pressure accumulation pipe by the supply pump is maximized.
A fuel injection control apparatus for an accumulator type engine having a pumping control means that, a fuel pressure detecting means for detecting a fuel pressure in the accumulator piping, based on the detection result of the state detecting means, calculates a target fuel pressure a target fuel pressure calculation means, the start-up completion stage before the start of the previous SL engine, this start-up, a starter for starting the engine is a just became inoperative from the operating state, the engine Restart-time determining means for determining whether or not it is a restart when the start has failed; and the restart-time determining means determines that the current start is immediately after the starter changes from the operating state to the non-operating state. When it is determined that the engine is restarting when the engine has failed to start, the actual fuel pressure detected by the fuel pressure detecting means is calculated by the target fuel pressure calculating means. When it becomes the calculated target fuel pressure or the fuel injection control apparatus for an accumulator type engine, characterized by comprising a pumping control stop means to stop the pumping control by the pumping control means. 6. A high pressure fuel is supplied from a supply pump, and a pressure accumulating pipe for accumulating the high pressure fuel, a fuel injection means connected to the pressure accumulating pipe for injecting fuel into a cylinder of the engine, and a state of the engine State detection means for detecting the fuel injection means, based on the detection result of the state detection means, to inject the fuel in the pressure accumulation pipe to the determined cylinder; and pressure regulating means for regulating the fuel pressure supplied from the supply pump to the accumulator piping, in the start-up completion stage before the start of the previous SL engine, the pressure to increase the fuel pressure supplied to the accumulator pipe Controlling the adjusting means to execute a full-pressure feed control in which the supply of fuel to the pressure accumulation pipe by the supply pump is maximized.
A fuel injection control apparatus for an accumulator type engine having a pumping control means that, a fuel pressure detecting means for detecting a fuel pressure in the accumulator piping, based on the detection result of the state detecting means, calculates a target fuel pressure a target fuel pressure calculating means, the fuel opened by an opening operation of the own fuel opening means for reducing the fuel pressure in the accumulator piping at the completion of the starting stage before the start of the previous SL engine, the current start, the Immediately after the starter for starting the engine has changed from the operating state to the non-operating state, and a restart-time determining means for determining whether or not a restart is to be performed when the engine has failed to start, The restart-time determination means determines that the current start is immediately after the starter is changed from the operating state to the non-operating state, and is the restarting time when the start of the engine fails. In this case, when the actual fuel pressure detected by the fuel pressure detecting means becomes equal to or higher than the target fuel pressure calculated by the target fuel pressure calculating means, the fuel opening means is opened, and the fuel in the accumulator pipe is opened. A fuel injection control device for an accumulator type engine, comprising: a fuel release control means for reducing pressure. 7. The fuel injection control device for an accumulator type engine according to claim 2, wherein the fuel release means is a relief valve provided between the accumulator pipe and the fuel injection means, and A fuel injection control device for a pressure-accumulation engine, comprising: a valve mechanism provided in the fuel injection means and capable of releasing fuel during an initial invalid injection time when the fuel injection means is driven. .