JPS5856342Y2 - Gas diesel engine intake system - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an intake system for a gas diesel engine.

In general, in diesel engines, the temperature of the combustion gas is extremely high, so by overlapping the exhaust and intake processes of the cylinder, the blow-out of the cylinder at the time of overlap is a means of suppressing overheating of the cylinder based on the cooling effect of the air. This prevents the lifespan of various parts from being shortened and the engine output from decreasing due to increases in exhaust gas temperature.

However, in the case of a gas-diesel engine, fuel gas is always mixed into the intake air, so it is inevitable that fuel will be wasted by the amount of fuel gas that is discharged as the air blows through. was there.

The present invention has been made in order to eliminate the above-mentioned drawbacks. Specifically, the purpose of the present invention is to separate the intake air for use in the atrium from the intake air mixture for filling the cylinder, so that only air that is not mixed with fuel gas is used. An object of the present invention is to provide an intake system for a gas diesel engine that can improve the fuel consumption rate by blowing through the air, and to simplify a device for performing the above operation.

Hereinafter, the present invention will be explained based on an illustrated embodiment.

In the intake system of the embodiment, as shown in FIG. 1, a pair of intake ports 2 and 3 are formed in the cylinder head 1, with a main intake port 2 on the right side of the drawing and a sub intake port 3 on the left side. are both connected to the air supply branch pipe 4' branched from the main air supply pipe 4, and both suction ports 2 and 3 are connected to the air supply branch pipe 4'.
They are separated by a partition plate 4a, which ensures isolation of the internal air in both suction ports.

Note that a pair of exhaust ports are provided on the front side of the cylinder head 1 in the drawing.

Further, between each suction port 2, 3 and the cylinder 5, a main intake valve 6 and a sub-intake valve 7 for opening and closing the respective suction ports are provided. A fuel gas supply pipe 8 passes through a part of the pipe wall of the main intake port 2.
As the pipe is inserted, the tip opening nozzle 8a portion of the pipe is bent and opened in the direction of the Sekiguchi valve seating surface of the main suction port 2.

Therefore, the main and auxiliary intake valves 6 and 7 have their valve shafts projected in parallel above the cylinder head 1.
The above-mentioned valve shafts are pressed down and driven at both ends of a horizontal bar 10 that is supported by a pin 9 erected on the upper surface and driven up and down. The tip of a rocker arm 12 is driven by a valve drive cam via 11, and is pressed down.

Note that a horizontal bar 10 facing the upper end of the valve shaft of the main intake valve 6
A gap C of a required size corresponding to the valve timing deviation is provided between the bolt adjustment tool 13 on the lower surface, and a gap C is provided between the lower surface of the horizontal bar 10 facing the upper end of the valve shaft of the sub-intake valve 6. As a result, the main intake valve 6 is driven to open later than the opening timing of the auxiliary intake valve 7.

Since the intake device of the embodiment is configured as described above,
As shown in the operating characteristic line A in FIG. Only air is introduced into the cylinder 1 through the sub-intake port 3, and sufficient cooling effect is performed by blowing this intake air, while the main intake valve 6 is closed at the end of the exhaust process, as shown by characteristic line B. As a result, the intake air-fuel mixture generated in the main intake port 2 by the air from the main air intake pipe 4 and the fuel gas from the fuel gas supply pipe 8 flows into the cylinder 5 without almost blowing through. filled inside.

In the above, the partition plate 4a of the air supply branch pipe 4' functions to prevent the fuel gas from being enclosed toward the sub-intake port side while the main intake valve 6 is closed.

According to the intake system for a gas diesel engine according to the present invention, in addition to the main intake ports 1 to 1 for generating an air-fuel mixture,
In addition to adding a sub-intake port that allows only air to flow in,
While the auxiliary intake valve is driven at the timing of the normal intake stroke, the main intake valve is driven at a later time than the auxiliary intake valve timing, so only air is used during the overlap of the intake and exhaust strokes. This makes it possible to perform scavenging air cooling, which prevents unnecessary loss of fuel.
The fuel consumption rate of the engine can be reduced.

Here, according to the present invention, the valve shafts of the main and sub-intake valves that open and close the main and sub-intake ports are made to protrude above the cylinder head in parallel, and are pushed down by both ends of the lower surface of one elevating horizontal bar. As a result, the opening/closing mechanism of the main and sub-intake valves becomes simple, and the opening/closing timing of the main and sub-intake valves can be adjusted and set extremely easily and accurately.

Further, according to the present invention, a four-valve easel engine, which is generally produced in large quantities, is minimally modified to insert a fuel gas supply pipe, and furthermore, by providing a mechanism for pressing down the main and sub-intake valves using the horizontal bar. This has an excellent practical effect in that it can be used as a gas-diesel engine with a small absolute demand.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an intake system for a gas diesel engine showing an embodiment of the present invention, and FIG. 2 is a graph of the valve operating characteristics of the same system. 1... Cylinder head, 2... Main suction port, 3... Sub suction port, 4...
Intake pipe, 6...Main intake valve, 7...Sub-intake valve, 8...Supply pipe, 8a...Nozzle, 10...・Horizontal bar

Claims (1)

[Scope of utility model registration request] A main suction port, a sub suction port, and a pair of exhaust ports, both connected to the main air intake pipe, are formed in the cylinder head, and inside the main suction port, there is a main suction port extending through a part of the pipe wall of the main suction port. When the fuel gas supply pipe is inserted, the tip opening nozzle portion of the pipe is bent and opened in the direction of the opening valve seat surface of the main intake port, and the valve shaft of the sub-intake valve that opens and closes the sub-intake port is opened. and the valve shaft of the main intake valve that opens and closes the main intake port protrude parallel to the upper part of the cylinder head.
Further, a horizontal bar is supported on the upper part of the cylinder head so that both ends of the lower surface thereof face the protruding upper end of the by-product valve shaft, and can be driven up and down. The distance between the upper end of the secondary valve shaft and the lower surface of the horizontal bar is set so that in the free state, the distance between the upper end of the main valve shaft and the lower surface of the horizontal bar is longer than the distance between the upper end of the secondary valve shaft and the lower surface of the horizontal bar. An intake system for a gas diesel engine characterized by: