JP2008044568A - Fuel tank of construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel tank of construction machine capable of preventing suction of air through a fuel suction port when the amount of remaining fuel is reduced, preventing mixing of air into a fuel injection pump when an engine stops due to stop of fuel supply, and dispensing with the work for removing air from the fuel injection pump to facilitate restarting of the engine. <P>SOLUTION: This fuel tank 1 is provided with a fuel tank main body 3 for storing fuel in its inside, the fuel suction port 5 provided in a bottom part of the fuel tank main body 3, and an air suction prevention means 6 attached to the fuel suction port 5 to prevent suction of air. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel tank for a construction machine.

  In general, a construction machine such as a hydraulic excavator is equipped with a fuel tank. Conventionally, for example, a fuel tank 1 as shown in FIG. 5 is used, and the fuel tank 1 is disposed on the upper surface side. An oil reservoir 4 is formed on the bottom surface of a fuel tank main body 3 provided with a fuel replenishing port 2, and fuel is supplied to the bottom surface of the oil reservoir 4 by operating a fuel pump (not shown). It has a configuration in which a mouth 5 is provided.

  By the way, in the case of a construction machine such as a hydraulic excavator, the work is often performed on an inclined land. However, in the structure of the fuel tank 1 as shown in FIG. 5, the remaining amount of fuel is reduced and the liquid level is lowered. In this state, if the fuel tank body 3 is tilted together with the construction machine and the fuel suction port 5 is exposed from the liquid level of the fuel, the air cannot be sucked and the fuel cannot be sucked, and the engine stops. .

In order to improve such a phenomenon, conventionally, as shown in FIG. 6, two fuel inlets 5 are installed at both ends in the front-rear direction (the left-right direction in FIG. 6) in which the fuel tank main body 3 is mainly inclined. As shown in FIG. 7, the oil reservoir 4 formed on the bottom surface of the fuel tank main body 3 is configured such that the depth dimension is larger than the opening dimension with respect to the bottom surface of the fuel tank main body 3 (patent Reference 1) was used.
JP-A-5-56550

  However, in the conventional fuel tank 1 as shown in FIGS. 5 to 7, in any case, the fuel inlet 5 is exposed from the fuel level regardless of whether the fuel tank body 3 is inclined or not. As a result, the supply of fuel is interrupted and the engine is stopped, and the fuel suction port 5 sucks air and air is mixed into the fuel injection pump of the engine. It was necessary to remove air mixed in the pump.

  In view of such circumstances, the present invention can prevent air from being sucked from the fuel inlet when the remaining amount of fuel is reduced, and can prevent air from being mixed into the fuel injection pump when the engine is stopped due to the interruption of fuel supply. It is an object of the present invention to provide a fuel tank for a construction machine that can be prevented and can easily restart an engine without requiring an operation of removing air from the fuel injection pump.

The present invention includes a fuel tank body in which fuel is stored,
A fuel inlet provided at the bottom of the fuel tank body;
An air suction preventing means attached to prevent the air from being sucked into the fuel suction port is provided for a fuel tank of a construction machine.

  According to the above means, the following operation can be obtained.

  If configured as described above, even if the fuel suction port is exposed from the liquid level of the fuel and the fuel supply is interrupted and the engine is stopped, the air suction preventing means prevents air from being sucked from the fuel suction port. Since no air enters the fuel injection pump, it is possible to save the trouble of removing the air from the fuel injection pump when the engine is restarted.

In the fuel tank of the construction machine, the air suction prevention means,
A cylinder projecting upward from the bottom surface of the fuel tank body at the fuel suction port, and having a fuel circulation hole formed in the side surface;
When the fuel flows into the cylinder, the float is floated by buoyancy to open the fuel suction port, and when the fuel does not flow into the cylinder, the float loaded in the cylinder is closed. And a spherical valve body.

  Further, the fuel suction port to which the air suction preventing means is attached can be disposed at a plurality of locations at the bottom of the fuel tank body so that the fuel tank body is located at the opposite electrode in the tilting direction. When the fuel tank body is tilted and the fuel liquid level is biased toward one end of the fuel tank body with the remaining fuel level decreased and the liquid level lowered, the side immersed in the fuel Since the fuel flows into the cylinder of the air intake prevention means, the float type spherical valve body floats due to buoyancy and the fuel intake port is opened, so that the fuel can be sucked while being exposed from the liquid level of the fuel Since the fuel does not flow into the cylinder of the air suction prevention means on the side to be closed and the fuel suction port is blocked by the float type spherical valve body, it is possible to prevent the fuel suction port from sucking air. Result, engine There with Nakuseru that would stop, without mixing air to the fuel injection pump of the engine, it is possible to hardly cause variations in the engine rotation.

  According to the fuel tank of the construction machine of the first and second aspects of the present invention, it is possible to prevent the air from being sucked from the fuel suction port when the remaining amount of the fuel is reduced, and the engine is stopped due to the fuel supply interruption. The air injection into the fuel injection pump at the time can be prevented, and the engine can be easily restarted without the need for removing the air from the fuel injection pump.

  Furthermore, according to the fuel tank of the construction machine according to claim 3 of the present invention, in addition to the above effect, the fuel tank main body is inclined in a state where the remaining amount of fuel is reduced and the liquid level is lowered. Even in this case, the fuel suction performance can be ensured, and an excellent effect can be obtained that the occurrence of variations in engine rotation due to air mixing into the fuel injection pump of the engine can be prevented.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 3 show an example of an embodiment of the present invention, in which a fuel tank main body 3 in which fuel is stored, a fuel suction port 5 provided at the bottom of the fuel tank main body 3, and the fuel suction The fuel tank 1 is configured by including air suction preventing means 6 attached so as to prevent air from being sucked into the mouth 5.

  In the case of the illustrated example, the air suction preventing means 6 includes, as shown in FIGS. 2 and 3, a cylinder body 8 having a fuel circulation hole 7 formed in the side surface in the fuel suction port 5. A float type spherical valve body 9 that protrudes upward from the bottom surface and has a specific gravity smaller than the specific gravity of the fuel is loaded into the cylinder body 8. When the fuel flows into the cylinder body 8, the float type spherical valve body is loaded. While the body 9 floats due to buoyancy, the fuel suction port 5 is opened (see the state shown by the solid line in FIG. 2). On the other hand, when the fuel does not flow into the cylindrical body 8, the float type spherical valve body 9 sucks the fuel. The mouth 5 is closed (see the state indicated by the phantom line in FIG. 2).

  The diameter of the hole 10 opened in the upper surface of the cylindrical body 8 is at least smaller than the outer diameter of the float type spherical valve body 9 so that the float type spherical valve body 9 does not come out of the cylindrical body 8. .

  A pipe 11 connected to a fuel pump (not shown) is connected to the fuel suction port 5.

  Furthermore, in the fuel tank 1 shown in FIG. 1, the fuel supply port provided on the upper surface side of the fuel tank main body 3 is not shown.

  Next, the operation of the illustrated example will be described.

  1 and 2, when the air suction preventing means 6 is immersed in the fuel, the fuel flows into the cylindrical body 8 of the air suction preventing means 6 and floats spherically. Since the valve body 9 floats by buoyancy and the fuel suction port 5 is opened, fuel can be sucked.

  On the other hand, when the air suction preventing means 6 is exposed from the liquid level of the fuel, the fuel does not flow into the cylinder 8 of the air suction preventing means 6, and the float type spherical valve body 9 causes the fuel suction port. 5 is closed, so that air is not sucked from the fuel suction port 5 and air is not mixed into the fuel injection pump of the engine, so that it is not necessary to remove the air from the fuel injection pump when the engine is restarted. Is possible.

  Thus, it is possible to prevent air from being sucked from the fuel suction port 5 when the remaining amount of fuel is reduced, and to prevent air from being mixed into the fuel injection pump when the engine is stopped due to the interruption of fuel supply. The operation of removing air from the pump is unnecessary, and the engine can be easily restarted.

  FIG. 4 shows another example of the embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. 1 to 3 denote the same components, and the basic configuration is shown in FIGS. 3 is the same as that shown in FIG. 3 but is characterized in that the fuel tank body 3 inclines the fuel inlet 5 to which the air suction preventing means 6 is attached as shown in FIG. The fuel tank main body 3 is disposed at a plurality of locations at the bottom of the fuel tank main body 3 so as to be located at the opposite electrodes.

  In the example of FIG. 4, the fuel suction ports 5 to which the air suction preventing means 6 are attached are disposed at two locations in the front-rear direction (left-right direction in FIG. 4) of the fuel tank body 3. Needless to say, the fuel inlets 5 to which the suction preventing means 6 are attached may be disposed in two places in the left-right direction of the fuel tank body 3 (in a direction perpendicular to the paper surface of FIG. 4).

  As shown in the example of FIG. 4, the fuel suction ports 5 to which the air suction prevention means 6 are attached are arranged at a plurality of locations at the bottom of the fuel tank body 3 so as to be positioned at the opposite electrodes in the direction in which the fuel tank body 3 is inclined. Then, in a state where the remaining amount of fuel is reduced and the liquid level is lowered (see FIG. 4A), the fuel tank main body 3 is inclined and the fuel liquid level is biased toward one end side of the fuel tank main body 3. At that time (see FIG. 4B or FIG. 4C), the fuel flows into the cylindrical body 8 of the air suction preventing means 6 on the side immersed in the fuel, and the float type spherical valve body 9 is formed. Since the fuel suction port 5 is opened by floating due to buoyancy, the fuel can be sucked, while the fuel does not flow into the cylinder 8 of the air suction preventing means 6 on the side exposed from the liquid level of the fuel. The fuel suction port 5 is closed by the float type spherical valve body 9, so that the fuel suction port It is possible to prevent air from being sucked in. As a result, it is possible to prevent the engine from shutting down, and to prevent air from entering the fuel injection pump of the engine, thus making it difficult for the engine rotation to vary. Is possible.

  Thus, in the case of the example shown in FIG. 4, even when the fuel tank body 3 is tilted in a state where the remaining amount of fuel is reduced and the liquid level is lowered, the fuel suction performance can be ensured and the fuel can be secured. Inhalation of air from the suction port 5 can be prevented, and the occurrence of variations in engine rotation due to air mixing into the fuel injection pump of the engine can be prevented.

  In addition, the fuel tank of the construction machine of the present invention is not limited to the illustrated example described above, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

It is sectional drawing which shows an example of the form which implements this invention. It is a principal part expanded sectional view which shows the air suction prevention means in an example which implements this invention, Comprising: It is the II section equivalent figure of FIG. It is a perspective view which shows the air suction prevention means in an example of the form which implements this invention. It is sectional drawing which shows the other example of embodiment which implements this invention, Comprising: (a) is a figure which shows the state by which the fuel tank is arrange | positioned horizontally, (b) is a fuel tank inclined and arrange | positioned to one side. The figure which shows the state which exists, (c) is a figure which shows the state by which the fuel tank is inclined and arrange | positioned to the other. It is a partially broken side view which shows an example of the fuel tank of the conventional construction machine. It is a side view which shows the other example of the fuel tank of the conventional construction machine. It is a partially broken side view which shows the further another example of the fuel tank of the conventional construction machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel tank 3 Fuel tank main body 5 Fuel suction inlet 6 Air suction prevention means 7 Flow hole 8 Tube 9 Float type spherical valve

Claims (3)

A fuel tank body in which fuel is stored,
A fuel inlet provided at the bottom of the fuel tank body;
A fuel tank for a construction machine, comprising: an air suction preventing means attached to prevent air from being sucked into the fuel suction port. The air suction prevention means,
A cylinder projecting upward from the bottom surface of the fuel tank main body to the fuel suction port and having a fuel circulation hole formed in the side surface;
When the fuel flows into the cylinder, the float is floated by buoyancy to open the fuel suction port, and when the fuel does not flow into the cylinder, the float loaded in the cylinder is closed. The fuel tank for a construction machine according to claim 1, comprising a spherical valve body.   3. The fuel tank for a construction machine according to claim 2, wherein the fuel suction port to which the air suction preventing means is attached is disposed at a plurality of locations at the bottom of the fuel tank main body so as to be positioned at a counter electrode in a direction in which the fuel tank main body is inclined. .

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