JPH11303713A - Starter device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety and reliability by preventing the occurrence of an accident of explosion or the like in a starting air pipe system by inhibiting a mixture from combusting, even when the mixture reversely from into the starting air pipe system, by suppressing a rapid temperature rise and pressure rise of air in a starting air inlet main pipe at starting operation time. SOLUTION: In a starter device for an internal combustion engine guiding starting air via a starting air inlet main pipe 3 and inlet branch pipe 4 to a starting valve 6 provided in each cylinder of the engine, opening the starting valve 6 by action of control air fed from a starting air control valve 8, and introducing the starting air into the cylinder, so as to start the engine, an air reservoir 10 having a prescribed capacity is connected to the starting air inlet main pipe 3, a pressure and temperature rise of air therein is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting apparatus for an internal combustion engine started by starting air, such as a large marine diesel engine.

[0002]

2. Description of the Related Art In a large marine diesel engine, a starting valve is provided for each cylinder (cylinder cover), and starting air is injected into the cylinder from the starting valve after the top dead center of the piston by a starting air control valve. A starting air system is used to operate and start the engine.

FIG. 2 shows an example of a conventional starting air system for such a large marine diesel engine. In FIG. 2, 1
Is a starting air automatic stop valve for supplying high-pressure starting air, 3 is a starting air inlet main pipe through which the starting air is introduced from the automatic starting valve 1 via the communication pipe 2, and 4 is the starting air. A starting air inlet branch pipe 6 branched from the main pipe 3 to each cylinder 5 is a starting valve provided in each cylinder 5 and connected to each inlet branch pipe 4.

Reference numeral 8 denotes a starting air control valve linked to the crankshaft of the engine. Control air for opening and closing each of the starting valves 6 is supplied to each of the starting valves 6 via a control air pipe 11 at a predetermined timing. Supply. Reference numeral 7 denotes a control valve connecting pipe branched from the starting air inlet main pipe 3 and sending control air to the starting air control valve 8. The end of the starting air inlet main pipe 3 is a closed end 9.

In a large diesel engine having the above-mentioned starting air system, when the engine is started, the starting air automatic stop valve 1 is opened and the starting air pressurized to a high pressure (pressure about 25 kgf / cm ² ) is supplied to the starting air inlet main pipe 3. And the starting valve 6 of each cylinder 5 through each starting air inlet branch 4. On the other hand, a part of the starting air is branched to the control valve communication pipe 7 and reaches the starting air control valve 8.

Then, in conjunction with the rotation of the crankshaft,
At a predetermined timing, the starting air control valve 8 operates,
When the control air is sent to each cylinder 5 through the control air pipe 11, the start-up valve 6 is opened by the operation of the control air, and high-pressure start-up air is injected into the cylinder 5, and the piston after the top dead center is reached. By acting on it and pushing it down,
The institution is started.

[0007]

In the starting air system, high-pressure (25 kgf / cm ² 300 k) air accumulates in the starting air inlet main pipe 3 while the starting air automatic stop valve 1 is open during the starting operation. Since the flow of the starting air is rapidly blocked at the closed end 9 of the inlet main pipe 3, the pressure and temperature of the starting air rapidly increase at the closed end 9.

When the pressure and temperature of the starting air at the closed end portion 9 suddenly rise as described above, if the combustible air-fuel mixture in the cylinder 5 flows back due to a defective seat of the starting valve 6 or the like, the air-fuel mixture is started. When the high-temperature and high-pressure closed end 9 reaches the high-temperature and high-pressure closed end 9 as described above, the high-temperature starting air passes through the valve 6 and the starting air inlet branch pipe 4 and accumulates in the starting air inlet main pipe 3. As a result, the flammable air-fuel mixture stagnating in the starting air inlet main pipe 3 causes combustion, and causes an accident such as an explosion of the starting air pipe or a fire.

An object of the present invention is to suppress a sudden increase in temperature and pressure of the air in the main pipe of the starting air inlet at the time of starting operation, so that even if there is a backflow of the air-fuel mixture into the starting air pipe system, the combustion of the air-fuel mixture is prevented. It is an object of the present invention to provide a starting device for an internal combustion engine in which the occurrence of an accident such as an explosion of a starting air pipe system is prevented and safety and reliability are improved.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The gist of the present invention is that a starting valve provided for each cylinder of an engine is opened and closed by a starting air stop valve. The starting air is led through the starting air inlet main pipe and the inlet branch pipe branched from the inlet main pipe for each cylinder, and is controlled by the action of the control air sent from the starting air control valve operated in conjunction with the crankshaft of the engine. A starting device for an internal combustion engine, in which a starting valve is opened and the starting air is introduced into a cylinder and acts on a piston to start the engine, an air reservoir having a predetermined volume is provided in the starting air inlet main pipe. Being connected.

According to the above means, when the starting air automatic stop valve is opened and high-pressure starting air is introduced into the starting air inlet main pipe, the starting air entering the starting air inlet main pipe is transferred to the inlet main pipe. It is introduced into the connected reservoir. When the starting air expands in the air reservoir having the predetermined volume, the pressure of the starting air in the inlet main pipe is relieved, and the pressure and temperature rise are suppressed. As in the conventional case, the superheated air in the inlet main pipe is prevented from causing an ignition and burning.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIG. FIG. 1 is a configuration diagram of a starting device for a large marine diesel engine according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a starting air automatic stop valve for controlling supply and discharge of high-pressure starting air, and reference numeral 3 denotes a starting air inlet main pipe connected to the automatic stop valve 1 via a communication pipe 2. Reference numeral 6 denotes a starting valve attached to each cylinder 5 of the engine, and 4 denotes a starting air inlet branch pipe branched from the starting air inlet main pipe 3 and connected to each of the starting valves 6.

Reference numeral 8 denotes a starting air control valve linked to a crankshaft (not shown) of the engine. Control air for opening and closing each of the starting valves 6 is supplied at a predetermined timing to the control air pipe 1.
1 to each start valve 6. Reference numeral 7 denotes a control valve connecting pipe branched from the starting air inlet main pipe 3 and sending control air to the starting air control valve 8. The above configuration is the same as the conventional one shown in FIG.

In the present invention, an air reservoir 10 connected to the starting air inlet main pipe 1 is provided. That is, in FIG. 1, reference numeral 10 denotes an air reservoir, which is set to a predetermined volume and connected to the closed end 9 of the inlet main pipe 3.

Here, the volume of the air reservoir 10 is determined by the ratio L / L of the length L of the starting air inlet main pipe 3 to the inner diameter D of the pipe.
Set as D. Length L of the starting air inlet main pipe 3 =
In a large diesel engine having a diameter of 9000 mm and an inner diameter D of 150 mm, the volume of the air reservoir 10 is preferably about 300 l.

In a large diesel engine equipped with the above-mentioned starting air system, when the engine is started, the starting air automatic stop valve 1 is opened and the starting air pressurized to a high pressure (pressure of about 25 kgf / cm ² ) is supplied to the starting air inlet main pipe 3. And the starting valve 6 of each cylinder 5 through each starting air inlet branch 4. On the other hand, a part of the starting air is branched to the control valve communication pipe 7 and reaches the starting air control valve 8.

Then, in conjunction with the rotation of the crankshaft,
When the starting air control valve 8 is opened at a predetermined timing and the control air is sent to each cylinder 5 via the control air pipe 11, the starting valve 6 of the cylinder 5 to which the control air is distributed opens. Then, high-pressure starting air is injected into the cylinder 5 and acts on the piston after the top dead center to depress it, thereby starting the engine.

At the time of the starting, when high-pressure starting air is introduced into the starting air inlet main pipe 3, the starting air is supplied to the air reservoir 1 connected to the closed end 9 of the inlet main pipe 3.
Introduced in 0. Then, in the air reservoir 10 having a predetermined volume, the starting air expands,
The pressure of the starting air in the inlet main pipe 3 is relaxed, and the pressure rise and the accompanying temperature rise are suppressed.

Accordingly, even if the air-fuel mixture flows backward from the cylinder 5 into the starting air inlet main pipe 3 due to a defective seat of the starting valve 6 or the like, the air in the inlet main pipe 3 becomes an ignition source and the air is mixed. Occurrence of a situation in which air is burned is reliably avoided.

[0021]

The present invention is configured as described above.
According to the present invention, since the air reservoir having a predetermined volume is connected to the starting air inlet main pipe, the starting air entering the inlet main pipe is introduced into the air reservoir and expanded.

As a result, the rise in pressure in the starting air inlet main pipe is moderated, and rises in air pressure and temperature are suppressed.
Even if the combustible air-fuel mixture flows backward from the cylinder into the starting air inlet main pipe, the starting air serves as an ignition source to prevent the air-fuel mixture from burning, and the combustion causes the air-fuel mixture to draw. An explosion or fire of the starting air pipe system can be prevented from occurring, thereby improving the safety of the engine.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a starting device for a large marine diesel engine according to an embodiment of the present invention.

FIG. 2 is an equivalent view of FIG. 1 showing a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 start air automatic stop valve 3 start air inlet main pipe 4 start air inlet branch pipe 5 cylinder 6 start valve 7 control valve communication pipe 8 start air control valve 9 closed end 10 air reservoir 11 control air pipe 100 engine

Claims (1)

[Claims] A starting air is introduced to a starting valve provided for each cylinder of an engine through a starting air inlet main pipe opened and closed by a starting air stop valve and an inlet branch pipe branched from the inlet main pipe for each cylinder. The start valve is opened by the action of control air sent from a start air control valve that operates in conjunction with the crankshaft of the engine, and the engine is started by introducing the start air into the cylinder and acting on the piston. In the starting apparatus for an internal combustion engine as described above, an air reservoir having a predetermined volume is connected to the starting air inlet main pipe.