JPH0346218Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a diesel engine, and particularly to an improvement in a fuel supply system of a diesel engine having a structure for recovering overflow fuel from a fuel injection nozzle.

[Conventional technology]

Conventionally, in the diesel engine, as shown in FIG. 3, the fuel overflowing from the fuel injection nozzle 10 was directly returned to the fuel tank 1 through the overflow pipe 7, but the following problems occurred in the fuel supply system. Occasionally, this occurred.

[Problem that the invention attempts to solve]

In equipment using a diesel engine, such as an agricultural vehicle such as a combine harvester, the fuel supply system is as shown in FIG. The fuel is sent to the fuel injection pump 6 of the engine 5 through. The fuel filter 3 is configured to release air bubbles contained in the fuel F into the fuel tank 1 through the air vent pipes 8 and 9, and at the same time remove fine dust from the fuel F with the element 3a. If the element 3a or the pipe 2 is partially clogged with this dust etc. and the fuel supply decreases, the feed pump 1
Due to the suction action of 5, the negative pressure inside the element 3a increases, and the liquid level of the air vent pipe 8 increases to the level of the pipe 4.
The air that has descended from the position of
There is a risk that the element 3a or the pipe 2
If the fuel tank 1 becomes completely clogged, the fuel supply from the fuel tank 1 is cut off, and the engine 5 must be stopped to interrupt any work.

An object of the present invention is to solve the above problem by using the fuel overflowing from the fuel injection nozzle 10.

[Means for solving problems]

The feature of the present invention is that the diesel engine fuel piping structure described above is configured as follows. In other words, connect the overflow pipe that collects overflow fuel from the fuel injection nozzle to the relay part,
This relay part and the fuel tank are connected by an air bleed pipe, and an air bleed pipe is provided to directly connect the downstream chamber of the element in the fuel filter and the relay part.

[Effect]

When configured as described above, for example, as shown in FIG. 1, overflow fuel from the fuel injection nozzle 10 is supplied to the relay section 12, and from this relay section 12, it is constantly and automatically passed through the air vent pipe 8b to the fuel filter. 3 is supplied to the downstream chamber 3b.
Further, the overflow fuel supplied to the relay section 12 is returned to the fuel tank 1 via the air bleed pipe 8a.

The air generated in the fuel filter 3 is guided to the fuel tank 1 via the air bleed pipe 8b, the relay section 12, and the air bleed pipe 8a.

In the above configuration, assume that element 3a of fuel filter 3 is partially clogged and fuel supply to fuel injection nozzle 10 decreases. In this case, since the overflow fuel from the fuel injection nozzle 10 is always automatically supplied to the downstream chamber 3b of the fuel filter 3 via the air bleed pipe 8b, the liquid level of the fuel in the air bleed pipe 8b suddenly increases. The fuel injection nozzle 10 does not drop, and air can be prevented from being sucked into the fuel injection nozzle 10.

Even if the element 3a of the fuel filter 3 is completely clogged, the engine can be operated for a certain period of time due to the above-mentioned overflow fuel.

[Effect of idea]

As explained above, since the intake of air in the fuel filter is avoided, malfunction of the engine due to intake of air in the fuel injection system is prevented. In addition, if the fuel filter is only slightly clogged, even if the fuel supply from the fuel tank becomes low, it will be replenished by the overflow fuel, so continuous operation will be possible, and the fuel filter will not be completely clogged. Even if the engine is overflowing, the engine can be operated for a certain amount of time, so instead of immediately stopping the engine and interrupting work, you can clean the fuel filter element at a suitable time or place that is well separated from work. , the maintainability of equipment using diesel engines has improved.

〔Example〕

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

FIG. 1 shows a fuel supply system for a combine harvester, which is one of the devices using a diesel engine. Fuel F stored in a fuel tank 1 having a fuel inlet 11 at the top thereof is supplied to a fuel injection pump 6 through a pipe 2, a fuel filter 3, a pipe 4, and a feed pump 15, and is then injected into a fuel injection nozzle 1.
0 into the combustion chamber 5a of the engine 5.

Air bubbles contained in the fuel F are guided into the fuel tank 1 through air bleed pipes 8 and 9 extending from the interior and exterior of the element 3a of the fuel filter 3. The remaining fuel F that overflows at the fuel injection nozzle 10 is supplied from the overflow pipe 7 to a chamber 12 (corresponding to a relay section) provided in the middle of the air vent pipe 8. This chamber 12 is the lower half 8b of the air vent pipe 8.
(corresponds to the air bleed pipe), and the inner chamber 3b (corresponds to the downstream chamber) of the element 3a of the fuel filter 3.
Since it is directly connected to chamber 1
The fuel F returned to the fuel tank 2 is always automatically supplied to the inner chamber 3b.

The fuel F returned to the chamber 12 is then returned to the fuel tank 1 through the upper half 8a (corresponding to the air vent pipe) of the air vent pipe 8.

The fuel tank 1 is connected to a cockpit 14 of a pilot section 13 provided on the front right side of the aircraft as shown in FIG.
The upper half 8a of the air vent pipe 8, which is installed on the rear side and returns overflow fuel to the fuel tank 1, is made of a transparent pipe, and the fuel tank 1 can be easily seen from the side of the cockpit 14 by the operator. It is connected to the. When the fuel filter 3a or the pipe 2 becomes clogged and the fuel supply from the fuel tank 1 decreases, the liquid level in the air bleed pipe 8 will drop due to the absorption effect of the feed pump 15. A blockage can be found by visually inspecting the half part 8a.

[Brief explanation of drawings]

The drawings show an embodiment of the fuel piping structure of a diesel engine according to the present invention, and FIG. 1 is a fuel piping system diagram, and FIG. 2 is a perspective view of the vicinity of the driver's seat of a combine harvester.
FIG. 3 is a conventional fuel piping system diagram. 1...Fuel tank, 3...Fuel filter, 3a
...Element, 3b...Downstream chamber, 7...Overflow pipe, 8a, 8b...Air vent pipe, 10...Fuel injection nozzle, 12...Relay part.

Claims (1)

[Scope of utility model registration request] The overflow pipe 7 for collecting overflow fuel from the fuel injection nozzle 10 is connected to the relay section 12.
The relay part 12 and the fuel tank 1 are connected to each other by an air vent pipe 8a, and the downstream chamber 3b of the element 3a in the fuel filter 3
This fuel piping structure for a diesel engine is provided with an air bleed pipe 8b that directly communicates and connects the relay part 12 and the relay part 12.