JP2000097039A - Fuel supplying device for engine working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a temperature rising of a fuel oil by disposing a fuel tank below a muffler and at a discharge side of a radiator, forming an upper corner portion of the fuel tank at the radiator side at a side at view to an approximately rectangular shape upwardly inclined from the radiator side to the far side of the radiator and providing a fuel supplement port at an upper portion of the fuel tank. SOLUTION: An internal fuel tank 6 self-contained in an engine working machine is disposed below a muffler 13 and at a far side from the engine 3 of the radiator 10. The internal fuel tank 6 is formed to an approximately rectangular shape inclined cut off an upper portion of the fuel tank 6 at the radiator 10 side at a side view and the cut off portion is formed to an inclined surface upwardly inclined as it progressives from the radiator 10 side from the radiator 10. The inclined surface is made to a guide surface 6a and a cooling wind passing from a cooling fan 3a through the radiator 10 and being approximately horizontally fed to the internal fuel tank 6 side is guided by the guide surface 6a and a wind-feeding direction is approximately upwardly changed. A fuel supplement port 6c for supplementing the fuel oil is disposed above the internal fuel tank 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for an engine working machine, and more particularly to a structure of an internal fuel tank,
And a fuel supply mechanism for the internal fuel tank.

[0002]

2. Description of the Related Art Conventionally, as an engine working machine, there is an engine working machine in which a working machine such as a generator and a pump driven by the engine is covered with a cover.
The engine working machine has a built-in internal fuel tank for storing fuel oil, and is arranged, for example, above a working machine such as a generator or an engine. Then, the fuel oil is supplied from the internal fuel tank to the fuel injection pump through the fuel supply pipe, the fuel oil is injected from the fuel injection pump into the engine, and the excess fuel oil supplied to the fuel injection pump is It was configured to return the fuel into the internal fuel tank through the fuel return pipe.

When the engine working machine is operated continuously for a long time, the capacity of the fuel oil is insufficient only with the internal fuel tank built in the engine working machine. An external fuel tank is provided to replenish fuel oil from the external fuel tank using a refueling pump when fuel oil in an internal fuel tank built into the engine working machine becomes smaller than a certain amount. . In this case, the upper fuel level detector and the lower fuel level detector are arranged vertically in the internal fuel tank built into the engine working machine, and the fuel level of the fuel oil is set higher than the set oil level of the lower fuel level detector below. When the oil level goes down, the fuel pump is activated to replenish the fuel oil from the external fuel tank, and the refueling is continued, and when the oil level of the fuel oil rises above the set oil level of the upper level detector, the fuel pump is turned on. Had been configured to stop.

[0004]

However, the engine working machine as described above has tended to be miniaturized in recent years, and an internal fuel tank built in the engine working machine is disposed above the working machine and the engine. As a result, the internal fuel tank is heated by heat generated from a working machine or an engine, and the temperature of fuel oil stored in the internal fuel tank has increased. The excess fuel oil returned from the fuel injection pump into the internal fuel tank has a high temperature, but since the fuel supply pipe and the fuel return pipe of the internal fuel tank are located close to each other, the internal fuel is returned through the fuel return pipe. In some cases, the fuel oil returned to the fuel tank is sucked into the fuel supply pipe at a high temperature and supplied to the fuel injection pump. As described above, when the temperature of the fuel oil supplied to the engine becomes high, there is a problem that the output of the engine is reduced and the working performance is deteriorated.

As described above, when replenishing the internal fuel tank built in the engine working machine with fuel oil from the external fuel tank, for example, if the upper level detector is out of order, the oil level of the fuel oil is reduced. However, even if the oil level rises above the set oil level of the upper level detector, the fuel supply pump does not stop, and the fuel oil may overflow. further,
When the oil level of the fuel oil drops below the set oil level of the lower level detector and attempts to replenish from the external fuel tank,
For example, if the fuel oil in the external fuel tank is empty, the oil level of the internal fuel tank built into the engine working machine does not rise, and the fuel pump continues to run idle, and the fuel pump Could be damaged.

[0006]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, in the fuel supply device for an engine working machine in which the working machine is attached to the engine output side, the fuel tank built in the engine working machine is disposed below the muffler and on the exhaust side of the radiator. The fuel tank is formed in a substantially rectangular shape in which the upper corner of the radiator side is cut obliquely in a side view, and the notched portion inclines upward from the radiator side to the anti-radiator side. The fuel tank was formed on an inclined surface, and a fuel supply port was provided above the fuel tank.

According to a second aspect of the present invention, there is provided a fuel supply device for an engine working machine having a working machine attached to an engine output side, wherein the fuel is supplied from the engine side into a fuel tank built in the engine working machine. In a configuration in which a fuel return pipe for returning fuel to the tank and a fuel supply pipe for supplying fuel from the fuel tank to the engine are inserted, and respective pipe ends are respectively disposed at an upper portion and a lower portion in the fuel tank. ,
A separating plate was interposed between both pipe ends.

According to a third aspect of the present invention, there is provided an engine working machine configured to be capable of supplying fuel oil to a fuel tank built in the engine working machine having a working machine attached to an engine output side by using a fuel pump. In the fuel supply device, a plurality of upper level detectors of fuel oil are vertically arranged within the fuel tank, and a plurality of lower level detectors of fuel oil are vertically disposed below the plurality of upper level detectors. When the oil level of the fuel oil is higher than the set oil level of each upper level detector and is lower than the set oil level of the lower lower level detector, When the pump stops and the oil level is located between the set oil levels of the upper and lower lower level detectors, the oil supply pump starts driving.

According to a fourth aspect of the present invention, in the fuel supply device for an engine working machine according to the third aspect, a forced operation operating tool for forcibly operating the fuel supply pump is provided.

[0010]

Next, an embodiment of the present invention will be described. FIG. 1 is a side view showing an engine working machine having a fuel supply device of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a plan view thereof, FIG. 4 is a side sectional view showing a cooling air inlet, and FIG. 4 is a side cross-sectional view showing a cooling air inlet different in form from the cooling air inlet, FIG. 6 is a plan cross-sectional view showing an internal fuel tank, FIG. 7 is a side cross-sectional view, FIG. 8 is a front cross-sectional view, and FIG. Is a side view showing the inside of another embodiment of the engine working machine, FIG. 10 is a perspective view showing an instrument box, FIG. 11 is a side view showing an upper float switch and a lower float switch provided in an internal fuel tank, and FIG. FIG. 13 is a diagram showing a circuit configuration for driving a pump, and FIG. 13 is a diagram showing a circuit configuration for driving a refueling pump provided with a return button as a forced operation operation tool.

First, the overall configuration of an engine working machine having the fuel supply device of the present invention will be described. 1 to 3
, The engine working machine 1 is provided with a cover 2 as an exterior component, and an engine 3 is installed in the cover 2, and is a working machine driven by the engine 3 on an output side of the engine 3. The generator 5 is connected. A cooling fan 3a provided with a flywheel is disposed on the side of the engine 3 opposite to the generator 5 (the flywheel side in the present embodiment), and the radiator 1 is opposed to the cooling fan 3a.
0, and an internal fuel tank 6 is disposed on the side of the radiator 10 opposite to the engine 3, and the cooling air blown out by the cooling fan 3 a of the engine 3 passes through the radiator 10 to the internal fuel tank 6 side. It is configured to flow to.

On both sides of the cover 2, cooling air inlets 2a
2b are formed, and the outside air is taken into the engine working machine 1 from the cooling air inlets 2a and 2b as cooling air. The cooling air introduced into the engine working machine 1 from the cooling air inlets 2a and 2b is sent to the radiator 10 by the cooling fan 3a while cooling the generator 5 and the engine 3, and is used for heat exchange. After passing through the exhaust passage 10, the air is exhausted to the internal fuel tank 6, and after cooling the internal fuel tank 6 and the muffler 13 disposed above the internal fuel tank 6, the exhaust air formed on the upper surface of the case 2 is cooled. The air is discharged to the outside from the wind port 2c.

The internal fuel tank 6 is formed in a substantially rectangular shape in which the upper part on the side of the radiator 10 is cut obliquely when viewed from the side, and the cut-out part is located on the side opposite to the radiator 10 from the radiator 10 side. The cooling air blown from the cooling fan 3a through the radiator 10 to the internal fuel tank 6 in a substantially horizontal direction is formed as a guide surface 6a. Guided by the surface 6a, the blowing direction is changed substantially upward, thereby facilitating the exhaust from the exhaust port 2c. That is, the guide surface 6a of the internal fuel tank 6 acts as a cooling air exhaust guide. The internal fuel tank 6
Conventionally, the work machine (generator 5) or the engine 3 which is apt to be high in temperature is arranged above the engine 3. In the present embodiment, the radiator 10 is arranged on the side opposite to the engine 3 and the guide surface such as this is used. By forming the fuel tank 6a, the heated air between the internal fuel tank 6 and the muffler 13 can be forcibly discharged to the outside of the engine working machine 1, and the temperature rise of the fuel oil in the internal fuel tank 6 can be reduced. Can be prevented. Further, by forming the guide surface 6a, there is no need to dispose the internal fuel tank 6 downward or on the side opposite to the radiator 10 in order to secure an exhaust passage from the radiator 10 to the vicinity of the muffler 18. 1 can contribute to downsizing of the whole, and it is possible to secure a large capacity of the internal fuel tank 6 in a limited space.

Above the internal fuel tank 6 (ie, above the upper surface 6b of the internal fuel tank 6), a fuel supply port 6c for supplying fuel oil to the internal fuel tank 6 is disposed. Although the fuel supply port 6c is arranged at a high position despite the arrangement of the fuel supply port 6 at a low position,
The refueling operation from the outside of the cover 2 to the internal fuel tank 6 is facilitated.

As shown in FIG. 4, a cooling air inlet 2a for introducing cooling air into the engine generator 1 has an opening 21 on the side surface of the cover 2 and goes upward inside the opening 21. The air guide passage 25 is formed by the inner plate 22.
An upper plate 23 is provided at the upper end of the air guide passage 25 so that the cooling air passing through the air guide passage 25 is introduced into the engine generator 1 in the cover 2 from the air inlet 26. A sound absorbing material 24 such as a sponge-like member or glass wool is attached to the lower surface of the upper plate 23 to absorb noise generated when cooling air is introduced into the engine generator 1 from the cooling air inlet 2a. Like that. The noise generated from the engine 3 and the generator 5 is absorbed by the sound absorbing material 24,
It is prevented from being blocked by the inner plate 22 and leaking to the outside.

The cooling air inlet 2b shown in FIG.
An opening 27 is opened on the side surface of the cover 2, and an air guide passage 30 is formed inside the opening 27 by inner plates 28 and 29. The air guide passage 30 extends upward from the opening 21 and then turns downward to extend to the air guide port 31.
Then, the cooling air that has entered through the opening 27 is
0 and is introduced into the engine generator 1 in the cover 2 from the air guide port 31. The noise generated from the engine 3 and the generator 5 is reduced by the inner plates 28 and 29.
And is prevented from leaking outside through the cooling air inlet 2b.

Next, the structure of the internal fuel tank 6 will be described with reference to FIGS. As shown in FIG. 8, an oil level gauge 40 is provided on one side surface of the internal fuel tank 6, and a drain pipe 41 is provided at a lower end of the internal fuel tank 6. On the upper surface of the internal fuel tank 6, a fuel supply pipe 35 for supplying fuel oil to the fuel injection pump of the engine 3, a fuel oil return pipe 36 for returning excess fuel oil from the fuel injection pump into the internal fuel tank 6, And engine working machine 1
An external fuel supply pipe 37 for supplying fuel oil from an external fuel tank provided outside the internal fuel tank 6 to the internal fuel tank 6 is inserted into the internal fuel tank 6 from above the internal fuel tank 6. The fuel supply pipe 35 has a pipe end (lower end) inserted to a lower portion in the internal fuel tank 6 and a fuel oil return pipe 3.
6 and the external fuel supply pipe 37 have their pipe ends (lower ends) inserted up to the upper part in the internal fuel tank 6.

In the internal fuel tank 6, below the pipe end of the fuel oil return pipe 36 and above the pipe end of the fuel supply pipe 35, a separation plate 38 is disposed in a substantially horizontal plate shape. I have. One side end of the separation plate 38 is fixed to one inner side surface of the internal fuel tank 6. Further, a substantially vertical plate-like reinforcing plate 3 is provided between the inner surface and the inner surface facing the inner surface.
9, the other side of the separation plate 38 is fixed to the upper end of the reinforcing plate 39. The separating plate 38 or the reinforcing plate 39 may be formed integrally with the internal fuel tank 6 using the same member. As shown in FIG. 6, in the separation plate 38 thus arranged, the internal fuel tank 6
The three side edges other than the one side edge fixed to one side surface are provided with a certain gap between each of the inner side surfaces of the internal fuel tank 6 opposed thereto.

In the internal fuel tank 6 configured as described above, when the fuel oil is returned from the fuel injection pump into the internal fuel tank 6 through the fuel oil return pipe 36, the fuel oil is supplied to the end of the fuel oil return pipe 36. (Lower end) from the separation plate 38
It will be dropped on the upper surface. The fuel oil that has fallen on the upper surface of the separation plate 38 spreads on the upper surface of the separation plate 38, falls downward from three edges of the separation plate 38 that are not in contact with the inner side surface of the internal fuel tank 6, and falls into the internal fuel tank 6. It is returned to the stored fuel oil.

Although the temperature of the fuel oil dropped from the fuel oil return pipe 36 is high, the fuel oil is cooled as it falls on the separation plate 38 and spreads, returns to a low temperature state, and is returned to the stored fuel oil. It will be. Thereby, especially when the level of the fuel oil stored in the internal fuel tank 6 is low, the high-temperature fuel oil from the fuel oil return pipe 36 is not cooled into the stored fuel oil. And can be prevented from being directly sucked into the fuel supply pipe 35 in a high-temperature state and sent to the fuel injection pump, and the working performance can be maintained without lowering the output of the engine 3. Becomes

Next, another embodiment of the engine working machine 1 will be described with reference to FIGS. As shown in FIG. 9, the engine working machine 1 of the present embodiment is provided with a cover 2 as an exterior component, an engine 3 is installed in the cover 2, and an engine 3 is provided on an output side of the engine 3. The generator 5 which is a working machine driven by 3 is connected. In the present embodiment, an internal fuel tank 6 is arranged above the generator 5, and the fuel oil stored in the internal fuel tank 6 is
The fuel is supplied to the fuel injection pump 8 via the fuel hose 7 and the fuel filter 18, and the fuel is injected into each cylinder of the engine 3 from the fuel injection pump 8. A radiator 10 is arranged on the side of the engine 3 opposite to the generator 5.
The exhaust from the engine 3 is configured to be exhausted to the outside from an exhaust tail pipe 19 through an exhaust pipe 17 and a muffler 13, and the exhaust pipe 17 is connected to the radiator 1 from above the engine 3.
0, the muffler 13 and the exhaust tail pipe 19 are also arranged on the anti-engine 3 side of the radiator 10, and the cooling fan of the engine 3 passes through the radiator 10 to exhaust the cooling air. So that it can be cooled.

In the engine working machine 1, an external fuel tank 43 is disposed outside the cover 2, and the external fuel tank 43 and the internal fuel tank 6 are connected by a fuel supply hose 44. In addition, fuel oil can be supplied from the external fuel tank 43 to the internal fuel tank 6. Further, an instrument box 15 is disposed on the side of the internal fuel tank 6, and the instrument surface is fitted into an opening provided in the cover 2. From the outside of the cover 2, the engine box 15 is used. Operations such as starting / stopping the work machine and replenishing fuel oil are performed. As shown in FIG. 10, a start switch 68 for starting the engine 3, a pump power indicator lamp 64 that lights up when the refueling pump 42 is operated, and an ammeter / voltmeter are provided on the instrument panel of the instrument box 15. Various instruments such as are arranged.
The external fuel tank 4 is provided on the side of the instrument box 15.
An external fuel tank pump power switch 63 for switching the state of automatic supply of fuel oil from the fuel tank 3 to the internal fuel tank 6;
In addition, a replenishment switch 67 that is operated when manually filling the fuel oil in the internal fuel tank 6 is provided.

As shown in FIG. 11, inside the internal fuel tank 6, a plurality of upper float switches FH ₁ are provided as upper level detectors for detecting an upper level which is an upper limit oil level of the stored fuel oil. A plurality of lower float switches F as lower level detectors for detecting FH ₂ and a lower level which is a lower limit oil level of the stored fuel oil;
L ₁ and FL ₂ are provided. The upper float switch F
H ₁ · FH ₂ are arranged vertically so that the upper float switch FH ₂ is located above the upper float switch FH ₁ , and the lower float switches FL ₁ · FL ₂ are
The lower float switch FL ₂ is connected to the lower float switch F
They are arranged vertically so as to be positioned below the L _1. Incidentally, the upper float switch FL ₁ located above the lower float switch FL _1.

The upper float switches FH ₁ and FH ₂ and the lower float switch FL ₁ are turned off when the oil level of the fuel oil is higher than these set oil levels and turned on when the oil level is lower. The lower float switch FL _2, the oil surface of fuel oil, are ON when in a level higher than the set fuel level is OFF when in the lower.

These upper float switches FH ₁ · F
H ₂ and the lower float switches FL ₁ and FL ₂ are shown in FIG.
Is configured to switch the operation / stop of the oil supply pump 42 according to the level of the fuel oil level, and to automatically supply the fuel oil from the external fuel tank 43 to the internal fuel tank 6. It is composed. That is, when the level of the fuel oil in the internal fuel tank 6 becomes lower than the lower float switch FL ₁ in the state where the pump power switch 63 for the external fuel tank is turned on, the upper float switch FH _1. FH ₂ and lower float switch FL ₁
Since both the FL ₂ are in the ON state, the relay 52 is turned ON, the contacts 52a and 52b of the relay 52 are closed, the fuel supply pump 42 is driven, and the pump power indicator lamp 64 is lit. Then, fuel oil is supplied from the external fuel tank 43 to the internal fuel tank 6. Are started and oil supply to the fuel tank 6, the oil level is lower level float switch FL ₁ when raised than the set fuel level of the lower float switch FL ₁ is turned OFF, the contacts 52 of the relay 52
Since a.52b is held by itself, refueling to the internal fuel tank 6 is continued. The refueling becomes full is continued, the oil level is also higher than set fuel level of the upper float switch FH _1, said upper float switch FH ₁
Is turned off, the relay 52 is turned off, the self-holding state is released, the contacts 52a and 52b are opened, the refueling pump 42 is stopped, and the pump power indicator lamp 6 is turned off.
4 turns off, and refueling to the internal fuel tank 6 stops.

Thereafter, when the oil level of the engine work machine 1 is continued and the oil level falls, and the oil level falls between the set oil levels of the upper float switch FH ₁ and the lower float switch FL ₁ , the upper float The switches FH ₁ and FH ₂ and the lower float switch FL ₂ are turned on, but the lower float switch FL ₁ is in the OFF state and the contacts 52 a and 52 _b of the relay 52 remain open.
2 is not driven and the internal fuel tank 6 is not refueled. The oil level further drops, and the lower float switch FL
If so positioned lower than the _first set oil level, switches the lower float switch FL ₁ is in the ON state, the oil supply pump 42 contacts 52a · 52 b is closed the relay 52 is driven, the fuel tank as described above Refueling to 6 is started.

Further, when oil supply to the fuel tank 6, for example, by failure upper float switch FH _1, elevated despite said upper float switch FH ₁ is OFF than the upper float switch FH ₁ is the oil surface when the oil pump 42 without being does not stop, the oil level up to the upper float switch FH ₂ which is arranged above the said upper float switch FH ₁ reaches, said upper float switch FH ₂ is being turned OFF, the oil supply The pump 42 is configured to stop. Thereby, even though the oil level has reached the upper limit oil level, refueling into the fuel tank 6 is continued without stopping the refueling pump 42, and the fuel oil overflows from the internal fuel tank 6. Can be prevented, and safety during refueling can be improved.

Also, when the oil level is lower than the float switch FL ₁
When the fuel supply from the external fuel tank 43 is started, the fuel oil in the external fuel tank 43 becomes empty or the external fuel tank 43 and the internal fuel tank 6 are connected. If fuel oil is not supplied to the internal fuel tank 6 due to a problem with the fuel supply hose 44 that is present, the oil level will further decrease and the refueling pump 42 will continue to run idle, as it is. . However, the lower the lower float switch FL ₁ by placing a lower float switch FL _2, the oil level is lower than the set fuel level of the lower float switch FL _2, as the lower level float switch FL ₂ is OFF since the construction, after the refueling of the external fuel tank 43 the oil level becomes lower than the set fuel level of the lower float switch FL ₁ is started, the setting of the lower float switch FL ₂ drops oil level further If the oil level is lower than the
The oil supply pump 42 can be stopped by opening the two contacts 52a and 52b.

Thus, when the internal fuel tank 6 is automatically refueled, the fuel oil in the external fuel tank 43 becomes empty or the fuel supply for connecting the external fuel tank 43 and the internal fuel tank 6 is replenished. When there is a problem with the hose 44, the refueling pump 42 can be prevented from running idle, and the refueling pump 42 can be prevented from being damaged. In this case, the oil level is set to the lower float switch FL ₂
It is also possible to have a configuration in which an alarm is issued at the time of lowering, such as turning on a warning light on the instrument panel of the instrument box 15 or sounding a warning sound.

[0030] When the refueling pump 42 oil level down than the set fuel level of the lower float switch FL ₂ is stopped, supply and fuel oil to the external fuel tank 43, the fuel supply hose 44 repair or replacement In order to restart the refueling pump 42 and supply the fuel oil to the internal fuel tank 6 after the treatment is performed, the oil level is set to the lower float switch FL.
_It is necessary to replenish the internal fuel tank 6 with fuel oil until it is positioned above the _second set oil level. Therefore,
Return button 5 which is a forced driving operation tool as shown in FIG.
By the provision of 5, by driving the oil pump 42 to raise the oil level to over setting fluid surfaces of the lower float switch FL _2, it is made possible to force return to automatic lubrication state to the fuel tank 6 . . That is, in the state where the oil level is lower than the set fuel level of the lower float switch FL _2, the upper float switch FH ₁ · FH ₂ and lower float switches FL ₁ is turned ON, the lower float switch FL ₂ is OFF Te, although the oil supply pump 42 is stopped, when oN operation of the reset button 55 provided in parallel to the lower float switch FL _2, closes the contact 52a · 52 b relay 52 is actuated to the oN side,
The refueling pump 42 is driven. The continued fueling of the reset button 55 to the inside of the fuel tank 6 while ON operation, the oil level rises above the pre-set fuel level of the lower float switch FL _2, since the lower level float switch FL ₂ is ON, After that, release the return button 55 and
Be returned to FF state, the relay 52a · 52 b is held in the closed state, therefore the oil supply pump 42 continues to drive, oil supply to automatically inside the fuel tank 6 until it reaches the set fuel level of the upper float switch FL ₁ is This is maintained, and the automatic refueling to the internal fuel tank 6 is restored.

[0031] Thus, by providing the reset button 55 to forcibly drive the oil supply pump 42, the oil level positioned below the lower float switch FL _2, is raised to lower the float switch FL ₂ or higher hand,
Automatic refueling from the external fuel tank 43 to the internal fuel tank 6 can be restored.

[0032]

As described above, the present invention has the following advantages. That is, in the fuel supply device for an engine working machine having a working machine mounted on the engine output side, a fuel tank built in the engine working machine is provided below the muffler and on the exhaust side of the radiator. The fuel tank is disposed, and in a side view, the upper corner portion of the radiator side is formed in a substantially rectangular shape with an oblique cutout, and the cutout portion is inclined upward from the radiator side to the anti-radiator side. Since the fuel supply port is provided in the upper portion of the fuel tank, the inclined surface of the fuel tank can function as a cooling air exhaust guide. Further, by forming such an inclined surface in the fuel tank, a cooling air passage formed by the inclined surface is used to allow the fuel tank to move between the muffler disposed above the fuel tank and the fuel tank. The heated air can be forcibly discharged to the outside of the engine working machine, and the temperature of the fuel oil in the fuel tank can be prevented from rising.
The muffler above the fuel tank can be effectively cooled. In addition, it is possible to secure a large capacity of the fuel tank built into the engine working machine in a limited space, and to secure the flow of cooling air from the radiator to the fuel tank by using the radiator. It is not necessary to shift the position greatly, which contributes to downsizing of the engine working machine. Further, even when the fuel tank is arranged at a low position, the fuel supply port is arranged at a high position, so that the refueling operation can be facilitated.

According to a second aspect of the present invention, there is provided a fuel supply device for an engine working machine having a working machine mounted on an engine output side, wherein the fuel supply device is provided in a fuel tank built in the engine working machine from the engine side. A structure in which a fuel return pipe for returning fuel to a fuel tank and a fuel supply pipe for supplying fuel from the fuel tank to the engine are inserted, and respective pipe ends are respectively disposed at an upper portion and a lower portion in the fuel tank. At
Since the separator is interposed between the two pipe ends, the fuel oil returned from the fuel return pipe into the fuel tank falls from the pipe end of the fuel return pipe to the upper surface of the separator, and the upper surface of the fuel return pipe returns to the upper surface of the separator. After being cooled in the diffusion process, the fuel oil is returned to the stored fuel oil, and particularly when the oil level of the fuel oil stored in the fuel tank is low, the fuel oil is returned from the fuel oil return pipe. The high temperature fuel oil falls without being cooled into the stored fuel oil, and is directly sucked into the fuel supply pipe in the high temperature state,
Delivery to the fuel injection pump can be prevented, and working performance can be maintained without lowering the output of the engine.

According to a third aspect of the present invention, an engine working machine is configured such that fuel oil can be supplied to a fuel tank built in the engine working machine having a working machine mounted on the engine output side by using a refueling pump. In the fuel supply device, a plurality of upper level detectors of fuel oil are disposed vertically above and below the fuel tank, and a lower level detector of fuel oil is vertically disposed below the plurality of upper level detectors. When a plurality of fuel oils are provided, the oil level of the fuel oil is higher than the set oil level of each upper level detector, and when the oil level of the fuel oil is lower than the set oil level of the lower level detector on the lower side. When the oil supply pump is stopped and the oil level is located between the set oil levels of the upper and lower lower level detectors, the oil supply pump starts driving, so that the oil level becomes the upper limit oil level. Refueling pump does not stop despite reaching Charge oil supply to the tank is continued, the fuel oil can be prevented from being overflowed from the fuel tank, it is possible to improve the safety during refueling. Also, during automatic refueling of the fuel tank,
For refueling, the fuel oil in the fuel tank outside the engine working machine for replenishing the fuel tank is empty or the fuel tank connecting the external fuel tank and the fuel tank inside the engine working machine is connected. It is possible to prevent the fuel pump from running idle even when fuel oil is not replenished in the internal fuel tank due to a malfunction of the hose or the like, thereby preventing damage to the fuel pump. .

According to a fourth aspect of the present invention, in the fuel supply device for an engine working machine according to the third aspect, a forced operation operating tool for forcibly operating the oil supply pump is provided, so that the fuel supply pump is disposed on the lower side. The oil level located below the set oil level of the lower level detector is raised to exceed the set oil level of the lower level detector, so that the refueling pump is automatically operated, and from the external fuel tank. The automatic refueling to the internal fuel tank can be returned.

[Brief description of the drawings]

FIG. 1 is a side view showing an engine working machine having a fuel supply device of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a plan view of the same.

FIG. 4 is a side sectional view showing a cooling air inlet;

FIG. 5 is a side sectional view showing a cooling air introduction port having a different form from the cooling air introduction port in FIG. 4;

FIG. 6 is a plan sectional view showing an internal fuel tank.

FIG. 7 is a side sectional view of the same.

FIG. 8 is a front sectional view of the same.

FIG. 9 is a side view showing the inside of another embodiment of the engine working machine.

FIG. 10 is a perspective view showing an instrument box.

FIG. 11 is a side view showing an upper float switch and a lower float switch provided in an internal fuel tank.

FIG. 12 is a diagram showing a circuit configuration for driving a refueling pump.

FIG. 13 is a diagram showing a circuit configuration for driving an oil supply pump provided with a return button as a forced operation operation tool.

[Explanation of symbols]

FH ₁ · FH ₂ upper float switch FL ₁ · FL ₂ lower float switch 1 engine working machine 2a · 2b cooling air inlet 2c exhaust outlet 3 engine 5 generator (working machine) 6 inside the fuel tank 6a guide surface 6c refueling port Reference Signs List 10 radiator 35 fuel supply pipe 36 fuel oil return pipe 37 external fuel supply pipe 38 separation plate 42 fuel supply pump 43 external fuel tank 44 fuel supply hose 55 return button

Claims (4)

[Claims] 1. A fuel supply device for an engine working machine having a working machine attached to an engine output side, wherein a fuel tank incorporated in the engine working machine is disposed below a muffler and on a discharge side of a radiator. The fuel tank, when viewed from the side, is formed in a substantially rectangular shape in which the upper corner of the radiator side is notched diagonally, and the notched portion is formed on an inclined surface which is inclined upward from the radiator side to the anti-radiator side. A fuel supply device for an engine working machine, wherein a fuel supply port is provided at an upper part of the fuel tank. 2. A fuel supply device for an engine working machine having a working machine mounted on an engine output side, for returning fuel from the engine side to the fuel tank in a fuel tank built in the engine working machine. A fuel return pipe and a fuel supply pipe for supplying fuel from the fuel tank to the engine, and the ends of the pipes are respectively arranged at the upper part and the lower part in the fuel tank. A fuel supply device for an engine working machine, wherein a separation plate is interposed in the fuel supply device. 3. A fuel supply device for an engine working machine, wherein a fuel oil is supplied to a fuel tank built in the engine working machine having a working machine attached to an engine output side by using a refueling pump. In the fuel tank, a plurality of upper level detectors of the fuel oil are disposed vertically, and a plurality of lower level detectors of the fuel oil are disposed below the plurality of upper level detectors, When the oil level of the fuel oil is higher than the set oil level of each upper level detector and when it is lower than the set oil level of the lower level detector on the lower side, the refueling pump is stopped, and A fuel supply device for an engine working machine, wherein the fuel supply pump starts driving when the oil level is located between the set oil levels of the upper and lower lower level detectors. 4. The fuel supply device for an engine working machine according to claim 3, further comprising a forced operation operating tool for forcibly operating the refueling pump.