JPH0235861B2 - SOKIATSURYOKUNYORUJIDONENRYOSEIGENCHOSEISOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic fuel limit adjustment system using scavenging pressure.

Generally, a main engine (diesel engine) of a ship or the like is provided with a pneumatic governor that controls output by adjusting the amount of fuel injection. As shown in Fig. 2, the governor controls its output along a torque limit line (indicated by a solid line) a based on the speed setting and a torque limit line (indicated by a broken line) b based on the scavenging pressure. It is being done. By the way, when starting the main engine, the torque limit line b based on the scavenging pressure is used, and according to this torque limit line b, for a short time after starting, for example, the amount of fuel equivalent to 60% load is used. The amount of fuel is injected and is set to be about 10% higher than the minimum amount required to start the main engine (equivalent to 5% load, indicated by the dashed line c in Figure 1), so that the speed can be increased immediately after starting. ing. However, the amount of intake air at startup is small, and if fuel equivalent to 60% load is injected into this air, a large amount of soot (smoke) will inevitably be produced.
This had the disadvantage of causing a negative impact on the engine system.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an automatic fuel limit adjustment device using scavenging pressure that can eliminate the above-mentioned drawbacks.

That is, the present invention provides a first line that sends control air pressure to an air governor for controlling fuel injection amount, and in the middle of the first line, a first switching valve and a second switching valve are installed in order from the upstream side to the downstream side. A valve is provided, and a second line is provided to send scavenging pressure from the scavenging pipe to the first switching valve,
A third line is provided to send the scavenging pressure in the second line to the second switching valve, and a fourth line is provided to send the working air pressure to operate the second switching valve. An air tank and a flow rate control valve are provided with a release means for releasing pressure, and are provided in the middle of the fourth line, and when the release means is operated to open, the operating air pressure is gradually released and the second switching valve is operated after a certain period of time. , the scavenging pressure is used as the operating pressure of the first switching valve, and when the engine is stopped, the second switching valve is operated by the operating air pressure in the fourth line, and the scavenging pressure is changed to the second switching valve. The minimum amount of fuel necessary for starting the engine is supplied to the air governor via the air governor line and the first line, and after the engine starts, the fourth line is The operating air pressure is gradually released, and after a certain period of time, the second switching valve is activated, and the control air pressure is sent to the air governor via the first line, which is greater than the minimum fuel injection amount required for engine rotation. The fuel injection amount necessary for speed increase is supplied, and when the scavenging pressure becomes higher than the control air pressure, the first switching valve is operated to transfer the scavenging pressure to the second line, the third line, and the control air pressure. This is an automatic fuel limit adjustment device using scavenging pressure, characterized in that the scavenging air is sent to an air governor via a first line.

According to this configuration, the minimum amount of fuel necessary for starting is injected for a certain period of time after starting the main engine, and after a certain period of time, the control air pressure is sent to the air governor and the amount of fuel required for speed increase is injected. Compared to the conventional case where the amount of fuel necessary for speed increase is injected from the start, the amount of smoke generated can be significantly reduced.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes a first line that sends control air pressure to an air governor 2 for adjusting fuel injection amount. , a first switching valve 4, a second switching valve 5, an emergency switching valve 6, and a second pressure reducing valve 7, and a relief line having a relief valve 8 between the second pressure reducing valve 7 and the air governor 2. 9 is connected. Reference numeral 10 denotes a second line that sends scavenging pressure from a scavenging pipe 11 that sends fresh air to the main engine (diesel engine) to the first switching valve 4. The first switching valve 4 opens the first line 1 during normal operation (position I), and connects the second line 10 to the first line during switching operation (position). That's what I do. 12 is a third line that sends the scavenging pressure in the second line 10 to the second switching valve 5. The second switching valve 5 opens the first line 1 in the normal state (position), and opens the first switching valve 4 in the first line 1 during the switching operation (position). The second line 10 is directly connected by bypassing the second line 10. Reference numeral 13 denotes a fourth line that sends operating air pressure for switching to the second switching valve 5, the end of which is linked to an operating lever (an example of opening means) in the main engine control room, and further along the way there is a control lever in the control room. A switching valve (an example of an opening means) 14, a flow rate control valve 15, and an air tank 16 are provided. When switching the second switching valve 5 from one position to another, the flow rate control valve 15 and the air tank 16 transmit the switching operation signal to the second switching valve 5 after a certain period of time.
It is for operating the. That is, first,
In a state in which working air pressure is sent into the fourth line 13, the second switching valve 5 is switched to the position, and the air tank 16 is filled with air,
When the fourth line 13 is opened to the atmosphere by the operating lever in the control room, the air in the air tank 16 gradually flows through the flow rate control valve 15, and the flow rate remains constant for a certain period of time (for example, 0 to 30 seconds). (It can be adjusted by the opening degree of the control valve 15.) Afterwards, the second switching valve 5 returns from the position to the position.

The wheelhouse switching valve 14 is actuated when the steering is performed only from the wheelhouse, and is used to switch the second switching valve 5 with priority over control by the control lever in the control room. It is something.
Therefore, the control lever in the wheelhouse is used to control the main engine from the wheelhouse, and the main engine can only be operated when the control lever in the control room is in the operating position. Furthermore, the operating lever in the control room is a lever that starts, runs, and stops the main engine, and is used when controlling the main engine from the control room.In this case, the operating air is supplied to the wheelhouse switch. It is supplied to the second switching valve 5 via the valve 14. Note that 17 is a fifth line that sends the scavenging pressure in the third line 12, that is, the second line 10, to the first switching valve 4 as the switching operation pressure. Therefore, the first switching valve 4 will not switch to the position unless the scavenging pressure increases until it overcomes the position return spring force of the first switching valve 4.

Next, starting the main engine will be explained. First, when the control lever for the wheelhouse is stopped, the first switching valve 4 is in the position because the scavenging pressure is zero, and the second switching valve 5 is in the position state since the scavenging pressure is zero.
4, the fourth line 13 is filled with operating air pressure and the position is switched. In this state, when the control lever in the wheelhouse is moved to the operating position, the main engine starts (the control lever in the control room is in the MAX operating position) and the fourth line 13 passes through the control valve 14 for the wheelhouse. Although it is opened to the atmosphere, the second switching valve 5 is still in the position at this time, so scavenging pressure is being sent to the air governor 2. During this startup, a preset required minimum fuel injection amount (for example, 50% load) can be supplied. Therefore, until the second switching valve 5 is switched, the fuel injection amount remains the minimum fuel injection amount necessary for starting, as shown by the solid line a in FIG. 3. Then, after a certain period of time, the second switching valve 5 is switched to the position, all the first lines 1 are connected, and control air pressure is sent to the air governor 2.
This control air pressure is determined by the amount of fuel injection required to increase the speed of the ship (for example, 60
Therefore, until the scavenging pressure rises and the first switching valve 4 switches to the position, the required fuel injection amount for speed increase is maintained as shown by the solid line b in Fig. 3. Supplied. Then, when the scavenging pressure rises and the first switching valve 4 switches to the position, the scavenging pressure is sent directly to the air governor 2, and after this, the fuel injection amount is set in advance as shown by the solid line c in Figure 3. Scavenging air is supplied along the pressure limit line. Note that the return spring force of the first switching valve 4 is set to a force corresponding to the fuel injection amount required for speed increase. Further, the emergency switching valve 6 in the first line 1 is operated during full speed reverse movement to send the highest pressure to the air governor 2.

According to the above configuration, the minimum amount of fuel required for starting is injected for a certain period of time after starting the main engine, and after a certain period of time, the control air pressure is sent to the air governor and the amount of fuel required for speed increase is injected. Therefore, compared to the conventional case where the amount of fuel required for speed increase is injected from the start, the amount of smoke generated can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention;
2 and 3 are drawings showing the relationship between the rotational speed of the main engine and the amount of fuel injection. FIG. 2 shows the case of the conventional example, and FIG. 3 shows the case of the present invention. 1...First line, 2...Air governor, 4...
First switching valve, 5...Second switching valve, 10...Second line, 11...Scavenging pipe, 12...Third line, 1
3... 4th line, 14... Wheelhouse switching valve, 1
5...Flow control valve, 16...Air tank, 17...
...5th line.

Claims (1)

[Claims] 1. A first line is provided to send control air pressure to an air governor for fuel injection amount adjustment, and a first switching valve and a second switching valve are provided in order from the upstream side to the downstream side in the middle of the first line, and the cleaning A second line is provided to send scavenging pressure from the trachea to the first switching valve, and
A third line is provided to send the scavenging pressure in the line to the second switching valve, and a fourth line is provided to send the working air pressure that operates the second switching valve, and the working air pressure is released in the middle of this fourth line. an air tank and a flow rate control valve are provided in the middle of the fourth line to gradually release the working air pressure and operate the second switching valve after a certain period of time when the opening means is operated to open; The scavenging air pressure is used as the operating pressure of the first switching valve, and when the engine is stopped, the operating air pressure in the fourth line operates the second switching valve, and the scavenging pressure is transferred to the second line and the operating air pressure. The minimum amount of fuel required to start the engine is supplied to the air governor through the first line, and after the engine is started, the working air in the fourth line is supplied by the opening operation of the opening means. The pressure is gradually released and the second switching valve operates after a certain period of time.
Control air pressure is sent to the air governor via the first line to supply a fuel injection amount necessary for speed increase that is greater than the minimum fuel injection amount required for engine rotation, and the scavenging air pressure is used for control purposes. The scavenging pressure is characterized in that when the pressure becomes higher than the air pressure, the first switching valve is operated to send the scavenging pressure to the air governor via the second line, the third line, and the first line. automatic fuel limit regulator.