JP2002103993A - Fuel feeding system for construction equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel feeding system for a hydraulic excavator capable of extending fuel supply interval. SOLUTION: This fuel feeding system 1 comprises a fuel tank 11, a suction line 12 connecting the fuel tank 11 with a fuel injection pump 31 of an engine 30, and a return line 14 connecting the fuel injection pump 31 with the fuel tank 11 for returning excess fuel. Enlargement of the inside diameter of the suction line 12 imparts a function as a fuel subtank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a fuel supply device for a construction machine typified by a hydraulic shovel, a crane, and the like, and more particularly, to a construction machine capable of extending a fuel supply time interval. In the technical field of the fuel supply device.

[0002]

2. Description of the Related Art A hydraulic excavator, which is an example of a construction machine, generally includes a lower traveling body, is turned around a vertical axis on the lower traveling body, and is composed of a boom and an arm. An upper revolving structure is provided which supports a bendable work arm on which a bucket is mounted so as to be able to move up and down, and has a driver's seat on one side of the work arm.

[0003] A hydraulic tank,
It consists of hydraulic equipment such as hydraulic pumps, hydraulic valves, hydraulic piping, etc., electric equipment such as batteries and harnesses, fuel tanks, suction lines for supplying fuel to the engine, and return lines for returning excess fuel to the fuel tanks. A fuel supply device is housed. The fuel tank of the fuel supply device having such a configuration seems to be slightly different depending on the manufacturer of the excavator. For example, the fuel tank is operated for 16 hours (operated for 8 hours a day for 2 days).
Generally, the capacity is set so that the fuel can be injected in an amount that can be operated without refueling.

[0004]

By the way, in the case of a mini excavator, an ultra-small swing type or an ultra-small swing type hydraulic excavator, an engine, an operator area, a hydraulic oil tank, etc., as long as the excavators have the same capacity. Although the layout space required for the installation of the equipment and devices does not change, the layout space for the upper revolving structure equipment and devices is narrow, and the space for disposing the fuel tank is limited. As the excavator becomes smaller, only a small-capacity fuel tank can be mounted. As a result, the fuel refueling time interval must be shortened, the operation cannot be performed for more than two days (16 hours) without refueling, and in some cases, the work must be interrupted to refuel. Becomes
There was a problem to be solved that the work efficiency was reduced.

Accordingly, an object of the present invention is to provide a fuel supply device for a construction machine, which makes it possible to extend a fuel supply time interval.

[0006]

Means for Solving the Problems The inventors of the present invention have generally used a hose or tube having an inner diameter of 8 to 10 mm for a suction line of a fuel supply device. However, if the suction line is provided with a function as an auxiliary fuel tank and the engine can be supplied with fuel in the suction line in addition to fuel in the fuel tank, the fuel tank can have a small capacity. Regardless, the present invention has been made on the assumption that the construction machine can be operated for a longer time without lubrication.

Therefore, in order to solve the above-mentioned problems, a feature of the means adopted by the fuel supply device for construction equipment according to claim 1 of the present invention is that a fuel tank is provided, and the fuel tank for the engine is provided from the fuel tank. A fuel supply device for a construction machine comprising a suction line for supplying fuel to an injection pump, and a return line for returning excess fuel from the fuel injection pump to the fuel tank. The inner diameter of the fuel tank is set to be larger than the inner diameter of the fuel tank to provide a function as a fuel sub-tank.

[0008] The feature of the means adopted by the fuel supply device for construction machinery according to claim 2 of the present invention is the feature of claim 1.
In the fuel supply device for a construction machine described in (1), fuel backflow prevention means for preventing backflow of fuel from the suction line to the fuel tank is provided near a connection between the suction line and the fuel tank. .

According to a third aspect of the present invention, there is provided a fuel supply system for a construction machine, wherein
In the fuel supply device for a construction machine described in (1), the fuel backflow prevention means is a throttle set to have a smaller diameter than an inner diameter of the suction line.

According to a fourth aspect of the present invention, there is provided a fuel supply system for a construction machine, wherein
In the fuel supply device for a construction machine described in (1), the throttle is a straight tube having a small inside diameter that connects the suction line and the fuel tank.

According to a fifth aspect of the present invention, there is provided a fuel supply system for a construction machine, wherein
In the fuel supply device for a construction machine according to any one of Items 4 to 4, the suction line is partially reduced in diameter.

According to the fuel supply device for a construction machine according to the first to fifth aspects of the present invention, fuel can be stored in the fuel tank and the suction line provided with a function as an auxiliary fuel tank, and The fuel can be supplied to the engine while preventing the fuel from flowing back from the suction line to the fuel tank by the fuel backflow prevention means. However, the liquid level of the fuel in the fuel tank is reduced by the fuel level stored in the suction line. Since the fuel can be supplied without any trouble until the fuel is reduced, the fuel supply time interval is extended and the operation time of the construction machine can be extended, which can greatly contribute to the improvement of work efficiency.

Further, according to the fuel supply system for a construction machine according to the fifth aspect of the present invention, the suction line is partially reduced in diameter to eliminate a portion that interferes with other equipment when the suction line is provided. Thereby, the arrangement work can be performed efficiently.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a fuel supply device for a construction machine according to an embodiment of the present invention will be described in a case where the construction machine is a micro-swing hydraulic excavator as an example. FIG. 1 for a state explanatory diagram and FIG. 2 for a configuration explanatory diagram thereof
And FIG. 3A for explaining the structure of the fuel backflow preventing means, and FIG. 3B for explaining the structure of the other fuel backflow preventing means.

Reference numeral 1 shown in FIG. 1 denotes a fuel supply device for a hydraulic shovel according to the present embodiment, and a fuel tank 11 of the fuel supply device 1 includes an upper revolving unit 20 of a micro-swing hydraulic excavator. The fuel tank 11 is configured to be able to supply fuel to the engine 30 housed at the rear of the upper revolving unit 20 from the fuel tank 11.

More specifically, as shown in FIG. 2, the fuel supply device 1
The suction line 12 in which the water separator 12 a attached to the engine 0 is interposed communicates with the fuel injection pump 31 of the engine 30. The suction line 12 has a function as a fuel sub-tank. That is, in the present embodiment, the inner diameter of the suction line 12 is 50 mm, and for example, when the hydraulic excavator is of a 2 ton class, the length is about 2 m.

The inner diameter of a suction line of a normal fuel supply device is 8 to 10 which is substantially the same as the inner diameter of a return line described later.
Since it is 10 mm, in the case of the suction line 12 having an inner diameter of 50 mm and a length of 2 m, the suction line 12 has an inner diameter of 3.times.
About 8 liters of extra fuel can be stored. Incidentally, this amount of fuel can drive an engine of about 11 KW mounted on a 2-ton class hydraulic excavator for about 2 hours.

The end of the suction line 12 is shown in FIG.
As shown in (a), the fuel tank 11 is externally fitted to a connection pipe 11a projecting from a lower side surface of the fuel tank 11, and is connected by being fastened by a hose clamp 12b. One end of the straight tube 13 serving as a fuel backflow prevention means projects into the fuel tank 11, and the other end projects into the suction line 12. The inner diameter of the straight tube 13 is set to 5 to 6 mm so as to exert an effect as a throttle, so that backflow of fuel from the suction line 12 to the fuel tank 11 can be effectively prevented. It is configured.

The fuel backflow prevention means does not necessarily have to be a straight tube 13, but has, for example, a small-diameter portion 15b at one end (fuel tank side) as shown in FIG. The reducer 15 having the large-diameter portion 15a at the end (on the suction line side) may be used.

Further, the fuel tank 11 is supplied from the fuel injection pump 31 of the engine 30 to the fuel tank 11.
A return line 14 having an inner diameter similar to that of a conventional example having an inner diameter of 8 to 10 mm is connected to return the excess fuel.

The operation of the fuel supply device 1 for a hydraulic shovel according to the above embodiment will be described below. As described above, the suction line 12 of the fuel supply device 1 according to the present embodiment is different from that of the conventional example. Although it has a large diameter, it can be arranged in a manner avoiding interference with each device housed in the upper swing body 20 as in the conventional example.

According to the fuel supply device 1 for a hydraulic shovel according to the present embodiment, the fuel tank 11 and the suction line 1 provided with a function as an auxiliary fuel tank are provided.
2 can store fuel, and the suction line 12
The fuel can be supplied to the engine 30 while preventing the fuel from flowing back to the fuel tank 11 from the fuel tank 11 until the liquid level of the fuel in the fuel tank 11 decreases by the amount of fuel stored in the suction line 12. Since the fuel supply can be performed without any trouble, the fuel supply time interval is extended, and the operation time of the hydraulic excavator can be extended. Therefore, an excellent effect that it can greatly contribute to improvement of work efficiency is produced.

In particular, in the case of a mini excavator equipped with a small engine, it is possible to greatly contribute to extending the fuel supply time interval.

The fuel tank 11 is provided with a liquid level, and when the liquid level of the fuel in the fuel tank 11 drops to a predetermined level, a warning lamp (not shown) is turned on. Normally, the warning lamp is set to light when the remaining fuel in the fuel tank becomes operable for about two hours. However, when the warning lamp is turned on, fuel is supplied.

However, in the case of the fuel supply device 1 according to the present embodiment, the warning lamp is turned on when the liquid level of the fuel in the fuel tank 11 decreases by the amount of the fuel in the suction line 12. It is not necessary to supply fuel until the amount of remaining fuel in the fuel tank 11 becomes smaller than in the conventional fuel tank.

In the above, the case where the inner diameter of the suction line 12 is 50 mm has been described as an example. However, the present invention is not particularly limited to the inner diameter of the suction line 12.
Although the case where the entire length of the suction line 12 has the same diameter has been described, for example, a portion where there is concern about interference with other equipment may be partially reduced in diameter. The technical scope of the present invention is not limited.

[0027]

As described in detail above, claim 1 of the present invention
According to the fuel supply device for a construction machine according to any one of (5) to (5), fuel can be stored in the fuel tank and the suction line provided with a function as an auxiliary fuel tank, and the fuel is prevented from flowing back from the suction line by the fuel backflow prevention means. The fuel can be supplied to the engine while preventing the fuel from flowing back into the fuel tank.However, the fuel must be supplied without interruption until the liquid level of the fuel in the fuel tank decreases by the amount of fuel stored in the suction line. Therefore, the fuel supply time interval is extended, and the operation time of the construction machine can be extended, so that there is an excellent effect that it can greatly contribute to the improvement of work efficiency.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a state in which a fuel supply device is housed in an upper-part turning body according to an embodiment of the present invention.

FIG. 2 is a configuration explanatory diagram of a fuel supply device according to an embodiment of the present invention.

3 (a) is an explanatory diagram of a configuration of a fuel backflow preventing unit, and FIG. 3 (b) is an explanatory diagram of a configuration of another fuel backflow preventing unit according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuel supply apparatus, 11 ... Fuel tank, 11a ... Connection pipe, 12 ... Suction line, 12a ... Water separator, 12b ... Hose clamp, 13 ... Straight tube, 14 ... Return line, 15 ... Reducer,
15a: Large-diameter portion, 15b: Small-diameter portion 20: Upper revolving body 30: Engine, 31: Fuel injection pump

Claims (5)

[Claims] 1. A fuel tank comprising: a fuel tank; a suction line for supplying fuel from the fuel tank to a fuel injection pump of an engine; and a return line for returning excess fuel from the fuel injection pump to the fuel tank. A fuel supply device for a construction machine, wherein an inner diameter of the suction line is set to be larger than an inner diameter of the return line, and a function as a fuel sub-tank is provided. 2. A fuel backflow preventing means for preventing backflow of fuel from the suction line to the fuel tank is provided near a connection between the suction line and the fuel tank. A fuel supply device for a construction machine according to claim 1. 3. The fuel supply device for a construction machine according to claim 2, wherein the fuel backflow prevention means is a throttle set to have a smaller diameter than an inner diameter of the suction line. 4. The fuel supply device for a construction machine according to claim 3, wherein the throttle is a straight tube having a small inside diameter connecting the suction line and the fuel tank. 5. The fuel supply device for a construction machine according to claim 1, wherein the suction line is partially reduced in diameter.