JPH06249022A - Inter-cylinder injection type engine - Google Patents

Abstract

PURPOSE:To prevent consumption of any wasteful time for starting an engine by properly judging a pressure condition for fuel injection in response to the situation of a preceding starting condition so as to properly start the engine, at the time of starting an inter cylinder injection type engine. CONSTITUTION:A fuel injection device 60 is arranged on the cylinder head 22 of an engine 11, and provided with an ignition plug 23 and an injector 24 facing to a combustion chamber 25. In this case, the fuel injection device 60 is connected to an air compressor 27 via a pipe passage 26, and high pressore air discharged from the air compressor 27 driven by a crank shaft 17 is introduced therein. The fuel injection device 60 is controlled in its drive by an ECU 38 via an injection driving circuit 36. Pressure inside the pipe passage 26 is recognized by the ECU 38, and a period from the time of starting the engine 11 to the operation of the fuel injection device 60 is delayed according to this recognated result. Consequently consumption of any wasteful time for starting the engine 11 can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injector for injecting and mixing fuel by injecting pressurized air into a combustion chamber in a cylinder, and ignition for burning an air-fuel mixture introduced into the combustion chamber of the cylinder. The present invention relates to a cylinder injection engine equipped with a device.

[0002]

2. Description of the Related Art For example, in a two-stroke engine, a scavenging port and an exhaust port are provided on a side wall of a cylinder.
Air is sent from the scavenging port to the combustion chamber in response to the reciprocating movement of the piston, and is mixed with the fuel injected by the pressurized air from the fuel injection device. It is a process of burning it and exhausting it from the exhaust port.

Such engine control is controlled by an engine control unit (ECU). This EC
Signals from various sensors such as an engine rotation angle sensor, a rotation speed sensor, and a pressure sensor are supplied to U, and fuel injection timing by the fuel injection device is based on the signals from these sensors. It also controls the operating state of the engine such as the fuel injection amount and the ignition timing of the spark plug by the ignition circuit.

[0004]

In the above two-cycle engine, since the pressure of the air sent to the fuel injection device by the compressor is low immediately after the engine is started, the operation of the fuel injection device is continued until this pressure exceeds a predetermined value. It is possible to stop (fuel injection).

That is, pressurized air can be supplied by the compressor at all times during engine startup, and even after the engine is stopped, the air pressure in the pipeline communicating between the compressor and the fuel injection device is maintained at a predetermined value. However, the pressure may decrease due to air leakage in the pipeline over time after the engine is stopped.

Even if the engine is started in such a state, proper fuel injection cannot be performed. Therefore, the engine can be started by injecting fuel after a lapse of a predetermined time from the start of the rotation of the crankshaft by the starter and the pressure of the air in the pipeline becomes the predetermined time or more.

[0007]

However, although such control is effective for starting the engine after a long time has elapsed after the engine is stopped, the pressure in the pipeline is normal for a short time after the engine is stopped. The fuel injection is always stopped for a certain period of time, even though the fuel injection is maintained at (above a predetermined value). Therefore, there is a problem in that it takes time to restart the engine despite the short time after the engine is stopped.

According to the present invention, when the engine is started, the pressure state for fuel injection is judged according to the history of the engine starting state before that, and an appropriate start is performed, so that the dead time can be omitted. The object is to obtain a cylinder injection engine that can be used.

[0009]

In order to achieve the above object, the present invention relates to an injection device for injecting and mixing fuel by injecting pressurized air into a combustion chamber in a cylinder, and a combustion chamber in the cylinder. In a cylinder injection engine equipped with an ignition device for burning the air-fuel mixture introduced into the compressor, a compressor for generating the compressed air and a pipeline for feeding the compressed air generated by the compressor to the injection device are provided. From the start of engine start to the operation of the injector according to the pressure state in the pipeline recognized by the pressurized air supply means, the pressure recognition means for recognizing the pressure in the pipeline, and the pressure state in the pipeline recognized by the pressure recognition means. And a delay means for delaying time.

[0010]

According to the present invention, when the compressed air is generated by the compressor, the compressed air is introduced into the injection device through the pipe line. In the injection device, the fuel generated by the ejection of the pressurized air can be drawn in to supply the fuel into the cylinder. Here, if you start the engine immediately after stopping the engine, there is no problem because the pressure in the pipeline is high, but after a long time after stopping the engine, the pressure of the air in the pipeline will drop and I cannot draw in fuel. Therefore, the pressure recognizing means recognizes the pressure in the pipeline, and delays the operation of the injection device according to the recognized pressure. Since the compressor is operating during this delay, the air pressure in the pipe becomes equal to or higher than a predetermined value, and the fuel can be reliably drawn into the cylinder.

Further, when the pressure recognized by the pressure recognizing means is high, the delay time is shortened, so that there is no wasted time and control can be performed according to the process up to the start of engine start. .

[0012]

EXAMPLES Next, examples of the present invention will be described. Figure 1
3 to FIG. 3 show a V-type 6-cylinder in-cylinder injection two-cycle engine 11 (hereinafter, simply referred to as engine 11) for a ship to which the present invention is applied. As shown in FIG. 3, the engine 11 is provided with an exhaust port 13 and a scavenging port 14 on a side wall of a cylinder block 12, and a piston 15 provided in the cylinder block 12 is reciprocally driven to open and close, respectively. It is like this.

The piston 15 is the connecting rod 1
6A and the crank arm 16B through the crank shaft 17
Are linked to. The crankshaft 17 of the engine 11 of this embodiment is arranged vertically. Figure 1 of the crankshaft 17
A rotor 50 forming a magnet is fixed to the upper end of the rotor 50, and a ring gear 52 is fixed to the outer periphery of the rotor 50. A crank angle sensor 54 is arranged around the ring gear 52, and its signal line has an EC described later.
It is connected to U38. With the crank angle sensor 54,
A pulse signal is output according to the rotation of the ring gear 52, and the crank angle and the position of the piston 15 can be recognized by counting the number of pulses.

When the engine is started, the starter 58 is turned on after the ignition switch 56 shown in FIG. 4 is turned on.
By operating (see FIGS. 2 and 4), the crank 17 is rotated. As shown in FIG. 2, the crank chamber 1 that accommodates the connecting rod 16A, the crank arm 16B, and the crank shaft 17 is shown.
An intake passage 20 faces 8 and a reed valve 19 and a throttle valve 21 are arranged in the intake passage 20.

A fuel injection device 6 having a spark plug 23 and an injector 24 on a cylinder head 22 located on the left side (upper part in FIG. 3) of the cylinder block 12 in FIG.
0 is provided, and the spark plug 23 and the injector 24 face the combustion chamber 25. The fuel injection device 60 is
The high pressure air discharged from the air compressor 27 driven by the crankshaft 17 is introduced into the discharge port of the air compressor 27 via the pipe line 26.

This fuel injection device 60 includes a regulator 2
8, communicated with the intake passage 20 via a pipe 29,
The high pressure air introduced into the fuel injection device 60 is regulated by the regulator 28, and the surplus high pressure air is returned to the intake passage 20 via the conduit 29. The fuel stored in the fuel tank 31 is supplied to the fuel injection device 60. This fuel is pressurized by the fuel pump 32, is suppressed in pulsation by the damper 33, and is then supplied through the conduit 34. Further, the regulator 35, which connects the fuel tank 31 and the conduit 34, has a role of adjusting the pressure of the fuel supplied to the fuel injection device 60 and a function of returning the excess fuel to the fuel tank 31.

The fuel injection device 60 is electrically connected to the injection drive circuit 36.
Thus, the timing of fuel injected from the injector 24 is controlled. The spark plug 23 is
It is electrically connected to the ignition circuit 37, and the ignition of the ignition plug 23 is controlled by the ignition circuit 37. The injection drive circuit 36 and the ignition circuit 37 are connected to the ECU 38.

As shown in FIG. 4, the ECU 38 includes a microcomputer 62, and the microcomputer 62 includes a CPU 64, a RAM 66, and a RO.
It is composed of an M68, an input / output port 70, and a bus 72 such as a data bus or a control bus connecting these. The input / output port 70 is provided with the crank angle sensor 54.
Is connected through the waveform shaping circuit 73, and the rotation speed sensor 7 for detecting the rotation speed of the crankshaft 17
The signal lines from 4 are connected. Further, the starter 58 is connected via a signal line of an ignition sensor 78 for detecting the on / off state of the ignition switch 56 and a driver 79. Further, the input / output port 70 is connected to a signal line that outputs an operation signal to the injection drive circuit 36 and the ignition circuit 37.

A main routine for controlling the injection drive circuit 36 and the ignition circuit 37 is preset and stored in the ROM 68. In the CPU 64, a detection signal, for example, a pulse of a pulse signal output from the crank angle sensor 54, is output. Count the number, recognize the position of the piston 15,
Predetermined fuel injection timing (scavenging port 14 and exhaust port 13
(In the closed state of), the drive signal is formed to generate the injection drive circuit 3
6, while supplying an output signal to the injection drive circuit 36
Generates an ignition signal at a predetermined ignition timing (compressed state) and supplies it to the ignition circuit 37. Further, the ROM 68 stores a subroutine for setting a fuel injection start delay time from the fuel injection device 60 when the engine is started.

This fuel injection start delay time is determined by the engine 1
It is set based on the history before the start of No. 1 start. That is, if a long time has passed since the engine 11 was stopped, the pressure in the pipe line 26 of the air sent from the air compressor 27 to the fuel injection device 60 may decrease. When this pressure drop occurs,
The fuel cannot be injected properly. Therefore, after the starter 58 is operated, the operation of the fuel injection device 60 is delayed for a predetermined time (relatively long time), and the fuel injection is waited until the pressure of the air in the pipe line 26 becomes a predetermined value or more. There is.

On the other hand, when the engine is restarted immediately after it is stopped, the pressure of the air in the conduit 26 has not dropped, and it is almost unnecessary to delay the fuel injection start time. Therefore, by starting the operation of the fuel injection device 60 within a predetermined time (relatively short time) after the starter 58 is operated, wasteful time is omitted. In this embodiment, depending on the history of the engine 11,
"No delay", "Short delay" and "Long delay" 3
The control of the stage is selected.

The operation of this embodiment will be described below. First,
The main routine of the engine drive control will be described with reference to FIG. In step 100, the ignition switch 5
If it is determined whether or not 6 is on and it is determined to be "yes" (affirmative determination), it is determined at step 101 whether the engine is being started, and if "no" is determined (negative determination), step 102 is performed. Engine 11 by starter 58
Startup control is performed. If the determination in step 101 is affirmative, step 102 is skipped and step 10 is performed.
Go to 4.

When the engine 11 is started by the starter 58 in step 102, step 104
Then, the pressurization time by the compressor 27 for starting the engine is set. The control in step 104 will be described later. In step 104,
The pressurization time is set, and when the set time has elapsed, fuel can be injected from the fuel injection device 60, and the routine proceeds to step 105. In step 105, the signal from the crank angle sensor 54 is acquired, and then in step 106, the number of the acquired pulses is counted. The position of the piston 15 can be recognized from this count value.

In the next step 108, it is judged whether or not it is the fuel injection timing, and in the case of a negative judgment, step 1
05, until the fuel injection timing is reached, that is, until an affirmative decision is made in step 108, steps 105, 1
06 and 108 are repeated. When an affirmative determination is made in step 108, the process proceeds to step 110, the fuel injection device 60 is operated, and fuel is injected. That is, the fuel is pressurized by the fuel pump 32, is suppressed in pulsation by the damper 33, is then sent to the injector 24 through the pipe 34, and is injected into the combustion chamber by the air at a predetermined pressure sent from the compressor 27. To be done. The fuel injection amount is determined by detection signals from the rotation speed sensor 74 and the pressure sensor 76.

In the next step 112, the signal from the crank angle sensor 54 is fetched, the number of pulses is counted in step 114, and then it is judged in step 116 whether it is the ignition timing. If it is determined in step 116 that it is the ignition timing, the routine proceeds to step 118, where the ignition circuit 37 is controlled to ignite the spark plug 23. That is, when the piston reaches the top dead center, the ignition plug 23 is ignited by the signal from the ignition circuit 37, the air-fuel mixture burns in the combustion chamber, and the piston 15 is pushed down. When the piston 15 descends, exhaust gas is discharged from the exhaust port 13 to complete one stroke, and the above main routine is repeated (step 1
The engine 11 continues to be driven by the negative determination (20). Further, when the affirmative determination is made in step 120, it is determined that the engine 11 has stopped, and step 12
At 2, the timer t is reset / started, and the processing ends. The timer t measures the time during which the engine 11 is stopped.

Next, the fuel injection timing delay control routine in step 104 will be described with reference to the flowchart of FIG. In step 150, the engine speed is detected, and then it is determined whether the speed detected in step 152 is equal to or higher than idling speed. Here, if the affirmative determination is made, it is determined that the engine 11 is already being driven, the process proceeds to step 154, the timer t is reset / started, and the process returns to the main routine.

[0027] In step 152, if a negative decision is made, whether or not the timer t indicates the engine stop time operation proceeds to step 156 is longer than the predetermined time t _a is determined,
In the case of a negative determination, it has been determined that the time has not passed since the engine 11 was stopped, that is, it is determined that the air in the pipeline 26 is maintained at a sufficient pressure, and the process returns. On the other hand, if an affirmative decision is made in step 156, then the routine proceeds to step 158, where _a predetermined time t _b longer than the predetermined time ta and the engine stop time t are compared. Here, when a negative determination is made, it is determined that t _b ≧ t> t _a , and it is determined that a relatively short time has elapsed after the engine is stopped, and the routine proceeds to step 160, where the fuel injection delay time t _STOP is shortened to the short time t. Substitute _S ,
Go to step 164. Further, when the affirmative determination is made in step 158 (t> t _b ), it is determined that a relatively long time has elapsed after the engine is stopped, and the routine proceeds to step 162, where the fuel injection delay time t _{STOP is set} to a long time t _l . Substitute and shift to step 164.

In step 164, the delay timer t _d is reset / started, and then in step 166, the delay timer t _d is compared with the fuel injection delay time t _STOP . When it is judged at this step 166 that t _d <t _STOP (affirmative judgment), the routine proceeds to this main routine, and the above-mentioned fuel injection control and ignition control of the engine are carried out. In this way, the fuel injection delay time is changed according to the time after the engine 11 has stopped, and when a relatively long time has elapsed since the engine 11 stopped, the air compressor 27 and the fuel injection device It is judged that the pressure of the air in the pipe 26 between the valve 60 and 60 is extremely low, and the fuel injection is delayed for a long time (t _L ). When the engine 11 has stopped for a relatively short time, it is determined that the pressure of the air in the conduit 26 between the air compressor 27 and the fuel injection device 60 is slightly low, and a short time ( t _S ) Delay fuel injection. Further, immediately after the engine 11 has stopped, it is determined that the pressure in the pipe line 26 is maintained at a predetermined value or higher, and fuel injection is not delayed. For this reason, it is possible to reduce the dead time until the engine starts while maintaining the engine startability, and it is possible to efficiently start the engine 11.

In this embodiment, the engine stop time is applied as the pressure recognizing means, and the fuel injection delay time is obtained based on the stop time of the engine 11. However, the fuel delay depends on the number of times the engine 11 is started. The time may be set (starting frequency control). That is, the control flow chart shown in FIG. 7 is applied as the delay time setting routine. The control of the number of times of starting will be described below. Regarding the steps of the same processing as in FIG.
The same step number is assigned and the description thereof is omitted.

In FIG. 7, in step 200, the number N of engine starts within a predetermined time is counted, and then in step 202 the number N of engine starts is the predetermined number N _a.
It is determined that the air in the pipe line 26 is maintained at a sufficient pressure in a short time after the final start of the engine 11, To return. On the other hand, if a negative decision is made in step 202, the routine proceeds to step 204, where the predetermined number N _b and the engine start number N less than the predetermined number N _a are set.
And are compared.

If a positive determination is made here, N _a ≧ N
> N _b , it is determined that the engine has been started a relatively small number of times, the process proceeds to step 160, the short time t _S is substituted for the fuel injection delay time t _STOP , and the process proceeds to step 164. Further, if a negative determination is made in step 204 (N ≦ N _b ), it is determined that the number of engine starts is extremely small, and the routine proceeds to step 162, where the fuel injection delay time t
Substituting a long time t ₁ into _STOP , the process proceeds to step 164. Even in such an engine start count, the pipeline 2
The pressure of the air in 6 can be recognized. Further, the pressure in the conduit 26 may be directly detected as the pressure recognition means (pressure detection control). The pressure detection control routine will be described below with reference to the flowchart of FIG. Note that the same step numbers are attached to the steps of the same processing as in FIG.

In step 250, the pressure P in the pipeline 26 is set.
To detect. Next, the pressure P detected in step 252 is compared with the predetermined pressure P _a, and if P> P _a , the pipeline 2
It is judged that the air in 6 is kept at a sufficient pressure, and the process returns. When it is determined in step 252 that P ≦ P _d , the process proceeds to step 254 and the predetermined pressure P
low and predetermined pressure P _b and the pipe internal pressure P is compared than _a. Here, when P> P _b (that is, P _a ≧
P> P _b ), it is determined that the pressure in the pipeline 26 has slightly decreased, and the routine proceeds to Step 160, where the short time t _S is substituted for the fuel injection delay time t _STOP , and then the routine proceeds to Step 164. Further, when it is determined in step 254 that P ≦ P _b, it is determined that the pressure in the pipeline 26 has dropped considerably,
The process proceeds to step 162, and the fuel injection delay time t _STOP is substituted with the long time t _l, and the process proceeds to step 164.

In the embodiment described above, the delay control for starting the operation of the fuel injection device has been described in two stages of "short-time delay" and "long-time delay". However, it should be controlled in a plurality of stages. You can also It can also be controlled to a continuous value. The delay control can be executed by combining the "timer control", the "starting number control", and the "pressure detection control".

[0034]

As described above, according to the present invention, when the engine is started, the pressure state for fuel injection is judged according to the history of the engine starting state before that, and the proper starting is performed. It is possible to provide an in-cylinder injection type engine in which it is possible to omit wasting time for starting the engine.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a two-cycle engine according to the present embodiment.

FIG. 2 is a top view of the engine shown in FIG.

FIG. 3 is a cross-sectional view showing the internal structure of one cylinder of the engine shown in FIGS. 1 and 2.

FIG. 4 is a control block diagram.

FIG. 5 is a control flowchart showing a main routine for driving the engine of the present embodiment.

FIG. 6 is a control flowchart (timer control) showing a subroutine for setting a fuel injection delay time at engine startup according to the present embodiment.

FIG. 7 is a control flow chart showing a modified example of a subroutine for setting a fuel injection delay time at the time of engine start (start count control).

FIG. 8 is a control flowchart showing a modified example of a subroutine for setting a fuel injection delay time at the time of engine start (pressure detection control).

[Explanation of symbols]

 11 Engine 23 Spark Plug 24 Injector 36 Injection Drive Circuit 37 Ignition Circuit 38 ECU 60 Fuel Injection Device 62 Microcomputer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F02N 11/08 Y 8614-3G

Claims (1)

[Claims] 1. An injection device for drawing in and mixing fuel by injecting pressurized air into a combustion chamber in a cylinder,
In an in-cylinder injection engine equipped with an ignition device for burning the air-fuel mixture introduced into the combustion chamber of the cylinder,
A compressor for generating the compressed air and a pressurized air supply means having a pipe for sending the compressed air generated by the compressor to the injection device; and a pressure recognition means for recognizing the pressure in the pipe. A cylinder injection engine having a delay unit that delays the time from the start of the engine to the operation of the injection device according to the pressure state in the pipeline recognized by the pressure recognition unit.