U.S. patent application number 13/786586 was filed with the patent office on 2013-09-19 for device for supplying fuel to engine.
This patent application is currently assigned to KUBOTA CORPORATION. The applicant listed for this patent is KUBOTA CORPORATION. Invention is credited to Norifumi Adachi, Takahiro Hisada, Mitsuhisa Kanata, Mamoru Kawaguchi, Akiyoshi Ono, Hisashi Tsukatani, Daisuke Yasunobe.
Application Number | 20130240066 13/786586 |
Document ID | / |
Family ID | 47844104 |
Filed Date | 2013-09-19 |
United States Patent
Application |
20130240066 |
Kind Code |
A1 |
Ono; Akiyoshi ; et
al. |
September 19, 2013 |
Device for Supplying Fuel to Engine
Abstract
A merge and discharge unit has: a reservoir unit in which fuel
can be collected; a first merge unit for merging into the reservoir
unit the fuel from an upstream site upstream of the merge and
discharge unit on a fuel supply route; a second merge unit for
merging into the reservoir unit the fuel from a first fuel return
route; a first discharge unit for discharging a portion of the fuel
of the reservoir unit into a downstream site downstream of the
merge and discharge unit on the fuel supply route; and a second
discharge unit for discharging a remaining portion of the fuel of
the reservoir unit into a second fuel return route.
Inventors: |
Ono; Akiyoshi; (Sakai-shi,
JP) ; Hisada; Takahiro; (Sakai-shi, JP) ;
Kawaguchi; Mamoru; (Sakai-shi, JP) ; Yasunobe;
Daisuke; (Sakai-shi, JP) ; Adachi; Norifumi;
(Sakai-shi, JP) ; Tsukatani; Hisashi; (Sakai-shi,
JP) ; Kanata; Mitsuhisa; (Sakai-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KUBOTA CORPORATION |
Osaka-shi |
|
JP |
|
|
Assignee: |
KUBOTA CORPORATION
Osaka-shi
JP
|
Family ID: |
47844104 |
Appl. No.: |
13/786586 |
Filed: |
March 6, 2013 |
Current U.S.
Class: |
137/565.01 |
Current CPC
Class: |
F02M 37/0088 20130101;
Y02T 10/126 20130101; F02M 37/0052 20130101; F02M 37/0058 20130101;
Y02T 10/12 20130101; F02M 37/0082 20130101; F02M 37/0023 20130101;
F02M 37/24 20190101; F02M 31/20 20130101; F02M 31/16 20130101; Y10T
137/85978 20150401; F02M 37/32 20190101; F02M 37/54 20190101; F02M
37/04 20130101 |
Class at
Publication: |
137/565.01 |
International
Class: |
F02M 37/22 20060101
F02M037/22 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 14, 2012 |
JP |
2012-057801 |
Mar 16, 2012 |
JP |
2012-060824 |
Claims
1. A device for supplying fuel to an engine, the fuel supply device
comprising: a fuel tank; a fuel supply route for supplying to the
engine fuel that has been collected in the tank; a filter provided
to the fuel supply route; a first fuel pump provided downstream of
the filter in a fuel supply direction on the fuel supply route; a
merge and discharge unit for merging and discharging fuel, the
merge and discharge unit being provided to a site between the fuel
tank and the filter on the fuel supply route; a first fuel return
route for returning the fuel of the engine to the merge and
discharge unit; and a second fuel return route for returning to the
fuel tank the fuel discharged from the merge and discharge unit;
wherein: the merge and discharge unit has: a reservoir unit in
which fuel can be collected; a first merge unit for merging into
the reservoir unit the fuel from a site upstream of the merge and
discharge unit on the fuel supply route; a second merge unit for
merging into the reservoir unit the fuel from the first fuel return
route; a first discharge unit for discharging a portion of the fuel
in the reservoir unit to a site downstream of the merge and
discharge unit on the fuel supply route; and a second discharge
unit for discharging a remaining portion of the fuel in the
reservoir unit into the second fuel return route.
2. The device for supplying fuel to an engine as in claim 1,
wherein: the amount of fuel discharged from the second discharge
unit is less than the amount of fuel discharged from the first
discharge unit.
3. The device for supplying fuel to an engine as in claim 2,
wherein: in causing the amount of fuel discharged from the second
discharge unit to be less than the amount of fuel discharged from
the first discharge unit, a constricted site where the flow path
cross-sectional area is less than that of the first discharge unit
is provided to the second discharge unit, or a constricted site
where the flow path cross-sectional area is less than that of the
downstream site on the fuel supply route is provided to the second
fuel return route.
4. The device for supplying fuel to an engine as in claim 1,
wherein: the first merge unit, the second merge unit, and the first
discharge unit of the merge and discharge unit are arranged in
sites below the reservoir unit, and the second discharge unit is
arranged at a site above the reservoir unit.
5. The device for supplying fuel to an engine as in claim 1,
wherein: a moisture removal unit for removing moisture included in
the fuel is arranged at a site between the fuel tank and the merge
and discharge unit on the fuel supply route.
6. The device for supplying fuel to an engine as in claim 1,
wherein: a cooling unit for cooling the fuel is arranged at a site
between the merge and discharge unit and the filter on the fuel
supply route.
7. The device for supplying fuel to an engine as in claim 1,
wherein: a moisture removal unit for removing moisture included in
the fuel, a second fuel pump, the merge and discharge unit, a
cooling unit for cooling the fuel, a third fuel pump, the filter,
and the first fuel pump are provided to the fuel supply route in
the stated order from the upstream side in the fuel supply
direction.
8. A fuel supply device for supplying fuel to an engine, the fuel
supply device comprising: a fuel tank, the fuel tank including: a
bottom; a recessed reservoir unit for collecting fuel, the recessed
reservoir unit being recessed so as to be lower than other portions
on the bottom; a covering for covering the recessed reservoir unit
in a state where the fuel is permitted to flow into the recessed
reservoir unit; and an intake unit for taking in and drawing out
fuel inside the fuel tank, above the bottom of the fuel tank.
9. The device for supplying fuel to an engine as in claim 8,
wherein: the covering is adapted so as to cover a middle site of
the recessed reservoir unit as seen in plan view.
10. The device for supplying fuel to an engine as in claim 8,
wherein: the intake unit is supported by the covering, and is
configured so that the covering supporting the intake unit can be
inserted into or removed from the fuel tank.
11. The device for supplying fuel to an engine as in claim 8,
wherein: the covering is constituted of a cylindrical body having a
hollow space that communicates with the recessed reservoir unit,
and a lower end of the cylindrical body is formed so as to be
smaller than the recessed reservoir unit when seen in plan view and
is inserted into the interior of the recessed reservoir unit.
12. The device for supplying fuel to an engine as in claim 11,
wherein: an air discharge unit enabling air in the hollow space to
be discharged to the exterior of the cylindrical body is provided
to an upper site of the cylindrical body.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a device for supplying fuel
to an engine, the fuel supply device being provided with a fuel
supply route for supplying an engine with fuel collected in a fuel
tank, and a filter and a first fuel pump being provided to the fuel
supply route in the stated order from the upstream side of a fuel
supply direction.
[0003] 2. Description of the Related Art
[0004] In a fuel supply device of such description, impurities
included in the fuel are removed by the filter provided to the fuel
supply route, and the fuel from which the impurities have been
removed is supplied to the engine. Also, a fuel return route for
returning fuel coming from the engine to the fuel tank is provided,
so that surplus fuel in the engine is returned to the fuel tank by
the fuel return route.
[0005] In the fuel supply device of such description, although the
impurities are removed by the filter, in a case where
low-temperature fuel is being supplied to the filter, such as
initial start-up of the engine when in a cold climate, a problem
emerges in that deposited matter or the like is created from the
fuel and the filter is clogged by the deposited matter.
[0006] In view whereof, in a conventional fuel supply device, an
interconnecting flow path that creates communication between a
midway site of the fuel supply route and a midway site of the fuel
return route is provided, and a circulation valve of a
temperature-sensitive displacement type is provided to the
interconnecting flow path (see, for example, Japanese Laid-open
Patent Application 2007-16658).
[0007] In the apparatus described in Japanese Laid-open Patent
Application 2007-16658, the circulation valve opens the
interconnecting flow path in a case where the fuel temperature is
less than a predetermined temperature, whereby the comparatively
higher-temperature fuel returning from the engine to the fuel tank
is admixed into the fuel coming from the fuel tank and is supplied
to the filter. The temperature of the fuel being supplied to the
filter is thereby elevated, thus preventing clogging of the filter.
Also, the circulation valve closes off the interconnecting flow
path in a case where the fuel temperature is the predetermined
value or greater, whereby the full amount of surplus fuel coming
from the engine is returned to the fuel tank.
SUMMARY OF THE INVENTION
[0008] In the apparatus described in Japanese Laid-open patent
Application 2007-16658, because preventing the clogging of the
filter necessitates the furnishing of the circulation valve, which
has a temperature-sensitivity displacement body made of a bimetal
or the like, there is a corresponding increase in costs and in the
complexity of the configuration.
[0009] In view of the foregoing, there has been demand for a fuel
supply device for an engine that makes it possible to prevent
clogging of a filter.
[0010] A device for supplying fuel to an engine, as in the present
invention, comprises:
[0011] a fuel tank;
[0012] a fuel supply route for supplying to the engine fuel that
has been collected in the tank;
[0013] a filter provided to the fuel supply route;
[0014] a first fuel pump provided downstream of the filter in a
fuel supply direction on the fuel supply route;
[0015] a merge and discharge unit for merging and discharging fuel,
the merge and discharge unit being provided to a site between the
fuel tank and the filter on the fuel supply route;
[0016] a first fuel return route for returning the fuel of the
engine to the merge and discharge unit; and
[0017] a second fuel return route for returning to the fuel tank
the fuel discharged from the merge and discharge unit;
[0018] wherein:
the merge and discharge unit has: a reservoir unit in which fuel
can be collected; a first merge unit for merging into the reservoir
unit the fuel from a site upstream of the merge and discharge unit
on the fuel supply route; a second merge unit for merging into the
reservoir unit the fuel from the first fuel return route; a first
discharge unit for discharging a portion of the fuel in the
reservoir unit to a site downstream of the merge and discharge unit
on the fuel supply route; and a second discharge unit for
discharging a remaining portion of the fuel in the reservoir unit
into the second fuel return route.
[0019] According to this characteristic configuration, the fuel
from the fuel tank is supplied to the merge and discharge unit by
the upstream site of the fuel supply route, and the fuel from the
engine is returned to the merge and discharge unit by the first
fuel return route. In the merge and discharge unit, the fuel from
the fuel tank is supplied to the reservoir unit by the first merge
unit, the fuel from the engine is merged into the reservoir unit by
the second merge unit, and the merged fuel is collected in the
reservoir unit. Then, in the merge and discharge unit, a portion of
the fuel collected in the reservoir unit is discharged to the
downstream site of the fuel supply route by the first discharge
unit, and a remaining portion is discharged to the second fuel
return route by the second discharge unit.
[0020] In this manner, the merge and discharge unit makes it
possible to merge the fuel from the engine into the fuel from the
fuel tank, and possible to supply the merged fuel to the filter by
way of the downstream site of the fuel supply route. Thus, even at
such times as the initial start-up of the engine in a cold climate,
it is accordingly possible to merge fuel that has been heated by
heat generated from the engine or the like into the low-temperature
fuel from the fuel tank and supply comparatively high-temperature
fuel to the filter, thus making it possible to prevent clogging of
the filter. As a result, a circulation valve can be obviated; only
the merge and discharge unit need be provided, thus making it
possible to prevent clogging of the filter without incurring an
increase in cost or in complexity of the configuration.
[0021] However, of the fuel that is collected in the reservoir unit
of the merge and discharge unit, a remaining portion other than
what is discharged to the downstream site of the fuel supply route
is discharged to the second fuel return route by the second
discharge unit and is returned to the fuel tank. This makes it
possible to also properly return surplus fuel of the engine to the
fuel tank, while it is also possible to prevent clogging of the
filter.
[0022] In the foregoing configuration, preferably, the amount of
fuel discharged from the second discharge unit is less than the
amount of fuel discharged from the first discharge unit.
[0023] According to this characteristic configuration, of the fuel
that is collected in the reservoir unit in the merge and discharge
unit, the flow rate of fuel discharged from the second discharge
unit and returned to the fuel tank is less than the flow rate of
fuel discharged from the first discharge unit and supplied to the
filter and to the engine. Because the flow rate of fuel supplied to
the merge and discharge unit by the upstream site of the fuel
supply route is an amount corresponding to the flow rate of fuel
returned to the fuel tank from the merge and discharge unit, it is
possible to also lessen the flow rate of fuel supplied to the merge
and discharge unit from the fuel tank. This makes it possible to
further increase the flow rate by which the fuel from the engine is
merged into the fuel from the fuel tank, and possible to properly
elevate the fuel temperature of the fuel being supplied to the
filter, thus properly preventing clogging of the filter.
[0024] In the foregoing configuration, preferably, in causing the
amount of fuel discharged from the second discharge unit to be less
than the amount of fuel discharged from the first discharge unit, a
constricted site where the flow path cross-sectional area is less
than that of the first discharge unit is provided to the second
discharge unit, or a constricted site where the flow path
cross-sectional area is less than that of the downstream site on
the fuel supply route is provided to the second fuel return
route.
[0025] According to this characteristic configuration, for example,
causing the flow path cross-sectional area of the second discharge
unit to be less than the flow path cross-sectional area of the
first discharge unit makes it possible to provide the constricted
site to the second discharge unit. Similarly, causing the flow path
cross-sectional area of the second fuel return route to be less
than the flow path cross-sectional area of the downstream site on
the fuel supply route makes it possible to provide the constricted
site to the second fuel return route.
[0026] Merely by thus employing the simple configuration of
providing the constricted site to the second discharge unit or the
second fuel return route, it is possible to cause the amount of
fuel discharged from the second discharge unit to be less than the
amount of fuel discharged from the first discharge unit.
[0027] In the foregoing configuration, preferably, the first merge
unit, the second merge unit, and the first discharge unit of the
merge and discharge unit are arranged in sites below the reservoir
unit, and the second discharge unit is arranged at a site above the
reservoir unit.
[0028] According to this characteristic configuration, in a case
where air is included in the fuel, the supply of the fuel to the
reservoir unit makes it possible for the air included in the fuel
to rise to the site above the reservoir unit and be discharged from
the second discharge unit. Thus, even when air is included in the
fuel being supplied to the engine, this makes it possible to
properly remove the air with the merge and discharge unit.
[0029] In the foregoing configuration, preferably, a moisture
removal unit for removing moisture included in the fuel is arranged
at a site between the fuel tank and the merge and discharge unit on
the fuel supply route.
[0030] According to this characteristic configuration, it is
possible to supply to the engine fuel after moisture include
therein has been removed by the moisture removal unit, and fuel
that does not include moisture can be properly supplied to the
engine. Also, as described above, causing the amount of fuel
discharged from the second discharge unit to be less than the
amount of fuel discharged from the first discharge unit makes it
possible to lessen the flow rate of fuel supplied to the merge and
discharge unit by the upstream site of the fuel supply route, and
thus it is possible to reduce the processing capability required
for the moisture removal unit, and the size and cost of the
moisture removal unit can be successfully lowered.
[0031] In the foregoing configuration, preferably, a cooling unit
for cooling the fuel is arranged at a site between the merge and
discharge unit and the filter on the fuel supply route.
[0032] According to this characteristic configuration, in a case
where the fuel temperature is an excessively high temperature,
cooling the fuel with the cooling unit makes it possible to lower
the fuel temperature of the fuel being supplied to the engine to a
desired temperature range. Moreover, as described above, providing
the merge and discharge unit causes the fuel from the engine to be
merged into the fuel from the fuel tank, and thus in a case where,
for example, the engine is continuously operated, it is conceivably
possible that the fuel temperature of the fuel being discharged
from the merge and discharge unit may reach an excessively high
temperature. In view whereof, providing the cooling unit to the
site between the merge and discharge unit and the filter on the
fuel supply route, as in this characteristic configuration, makes
it possible to cool the fuel temperature of the fuel being supplied
to the engine to a desirable temperature range, even when the fuel
temperature of the fuel being discharged from the merge and
discharge unit is an excessively high temperature.
[0033] In the foregoing configuration, preferably, a moisture
removal unit for removing moisture included in the fuel, a second
fuel pump, the merge and discharge unit, a cooling unit for cooling
the fuel, a third fuel pump, the filter, and the first fuel pump
are provided to the fuel supply route in the stated order from the
upstream side in the fuel supply direction.
[0034] According to this characteristic configuration, the moisture
removal unit is provided to the upstream site on the fuel supply
route, as is the second fuel pump. Then, as described above,
causing the amount of fuel discharged from the second discharge
unit to be less than the amount of fuel discharged from the first
discharge unit makes it possible to lessen the fuel flow rate being
supplied to the merge and discharge unit by the upstream site of
the fuel supply route, and thus it is possible to reduce the
processing capability required for the moisture removal unit, and
the size and cost of the moisture removal unit can be successfully
lowered, while also the capacity required for the second fuel pump,
too, can be reduced, and the size and cost of the second fuel pump
can be successfully lowered. Additionally, because the cooling unit
is also provided, the fuel temperature of the fuel being supplied
to the engine can be cooled to a desired temperature range even
when the fuel temperature of the fuel being discharged from the
merge and discharge unit reaches an excessively high temperature,
as described above.
[0035] A device for supplying fuel to an engine, as in the present
invention, comprises:
[0036] a fuel tank, the fuel tank including:
[0037] a bottom;
[0038] a recessed reservoir unit for collecting fuel, the recessed
reservoir unit being recessed so as to be lower than other portions
on the bottom;
[0039] a covering for covering the recessed reservoir unit in a
state where the fuel is permitted to flow into the recessed
reservoir unit; and
[0040] an intake unit for taking in and drawing out fuel inside the
fuel tank, above the bottom of the fuel tank.
[0041] According to this configuration, because the recessed
reservoir unit is provided to the bottom of the fuel tank, fuel can
be kept collected in the recessed reservoir unit even when there is
a lesser amount of fuel. Also, because the covering covers the
recessed reservoir unit, the covering makes it possible to prevent
the fuel that is collected in the recessed reservoir unit from
flowing outwardly therefrom, even when the fuel tank is swung in
the left/right direction and in the front/rear direction. The fuel
can accordingly be kept collected in the recessed reservoir unit
even when the fuel tank is swung in the left/right direction and in
the front/rear direction in a case where there is a lesser amount
of fuel. Because the intake unit takes in and draws out the fuel
that is collected in the recessed reservoir unit, the fuel can be
properly taken in without also taking in air, even when there is a
lesser amount of fuel in the fuel tank.
[0042] In the foregoing configuration, preferably, the covering is
adapted so as to cover a middle site of the recessed reservoir unit
as seen in plan view.
[0043] According to this configuration, because the covering covers
the middle site of the recessed reservoir unit, a spacing can be
formed between an outer peripheral part of the covering and an
inner peripheral part of the recessed reservoir unit, across the
full length of the outer periphery of the covering. Therefore, fuel
can be permitted to flow into the recessed reservoir unit from the
spacing, and even when there is a lesser amount of fuel, the fuel
can be properly kept collected in the recessed reservoir unit.
[0044] In the foregoing configuration, preferably, the intake unit
is supported by the covering, and is configured so that the
covering supporting the intake unit can be inserted into or removed
from the fuel tank.
[0045] According to this configuration, merely mounting the
covering supporting the intake unit onto the fuel tank makes it
possible for the intake unit and the covering to be mounted
together, and allows for the intake unit and the covering to be
easily mounted. In a case where the intake unit and the covering
are to be removed, the intake unit and the covering can similarly
be removed together. Moreover, because the intake unit is supported
by the covering, merely adjusting the position where the intake
unit is supported by the covering makes it possible to adjust the
relationship between the relative positions of the intake unit and
the covering. This makes it possible to readily mount the recessed
reservoir unit and the intake unit at proper positions, by mounting
the covering supporting the intake unit onto the fuel tank after
having adjusted the position where the intake unit is supported by
the covering.
[0046] In the foregoing configuration, preferably, the covering is
constituted of a cylindrical body having a hollow space that
communicates with the recessed reservoir unit, and a lower end of
the cylindrical body is formed so as to be smaller than the
recessed reservoir unit when seen in plan view and is inserted into
the interior of the recessed reservoir unit.
[0047] According to this configuration, because the cylindrical
body serving as the covering is arranged so that the lower end
thereof is inserted into the interior of the recessed reservoir
unit, the presence of the cylindrical body having been inserted
into the interior of the recessed reservoir unit makes it possible
to prevent swinging of the liquid level of the fuel that is
collected in the recessed reservoir unit, even when the fuel tank
is swung in the left/right direction and the front/rear direction.
It is accordingly possible to reliably prevent the fuel that is
collected in the recessed reservoir unit from flowing outwardly
therefrom. Moreover, the fuel can also be collected in the hollow
space of the cylindrical body inserted into the interior of the
recessed reservoir unit, thus making it possible to ensure a
correspondingly greater capacity of fuel that is taken in by the
intake unit.
[0048] In the foregoing configuration, preferably, an air discharge
unit enabling air in the hollow space to be discharged to the
exterior of the cylindrical body is provided to an upper site of
the cylindrical body.
[0049] According to this configuration, even when air is included
in the fuel that is collected in the recessed reservoir unit, it is
possible for the air to rise through the hollow space of the
cylindrical body and be discharged to the exterior of the
cylindrical body by the air discharge unit. This makes it possible
to remove air by using the cylindrical body, and therefore makes it
possible to properly prevent air from being taken in by the intake
unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] FIG. 1 is a schematic configuration diagram of a device for
supplying fuel to an engine;
[0051] FIG. 2 is a front view of a merge and discharge unit;
[0052] FIG. 3 is a side view of a merge and discharge unit;
[0053] FIG. 4 is a side view of a tractor;
[0054] FIG. 5 is a schematic view illustrating an arrangement
position of a merge and discharge unit in a tractor;
[0055] FIG. 6 is a side view of a tractor;
[0056] FIG. 7 is a plan view illustrating the inside of a
cabin;
[0057] FIG. 8 is a perspective view of a fuel tank;
[0058] FIG. 9 is a cross-sectional view of a fuel tank;
[0059] FIG. 10 is a perspective view illustrating the main parts of
a fuel tank;
[0060] FIG. 11 is a perspective view illustrating the arrangement
of a variety of operation levers in a cabin;
[0061] FIG. 12 is a cross-sectional view illustrating the main
parts of an auxiliary control lever;
[0062] FIG. 13 is a suction structure of a fuel tank in a separate
embodiment; and
[0063] FIG. 14 is a suction structure of a fuel tank in a separate
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0064] Embodiments of a fuel supply device for an engine as in the
present invention shall be described on the basis of the
accompanying drawings.
[0065] A fuel supply device 1 for an engine, as illustrated in FIG.
1, is provided with a fuel supply route 4 for supplying to an
engine 3 fuel that is collected in a fuel tank 2. Provided to the
fuel supply route 4 are a moisture removal unit 5, an
electromagnetic pump 6 (equivalent to a second fuel pump), a merge
and discharge unit 7, a cooling unit 8, a feed pump 9 (equivalent
to a third fuel pump), a filter 10, and a supply pump 11
(equivalent to a first fuel pump), in the stated order from the
upstream side in a fuel supply direction.
[0066] The engine 3 is, for example, a common-rail diesel engine
provided with a rail 3a and a plurality of injectors 3b, and is
adapted to be capable of electronically controlling the amount of
fuel injection and the injection timing. The moisture removal unit
5 is, for example, a sedimenter, and is adapted to remove moisture
that is included in the fuel. The merge and discharge unit 7 is
adapted to merge and discharge fuel flows. The cooling unit 8 is,
for example, a cooler, and is adapted to cool the fuel. The filter
10 is adapted to remove impurities that are included in the
fuel.
[0067] The fuel of the fuel supply route 4 firstly undergoes
moisture removal by the moisture removal unit 5 and is pressurized
by the electromagnetic pump 6, supplied to the cooling unit 8, and
cooled in the cooling unit 8 to a desired temperature range. The
fuel, having reached the desired temperature range, is pressurized
by the feed pump 9 and is supplied to the filter 10; the impurities
are removed by the filter 10. The fuel from which the impurities
have been removed is pressurized by the supply pump 11 and supplied
to the rail 3a of the common-rail engine 3.
[0068] In the fuel supply device 1, not only is the fuel supplied
to the engine 3 via the fuel supply route 4, but also provided are
a first fuel return route 12 via which the fuel of the engine 3 is
returned to the merge and discharge unit 7 and a second fuel return
route 13 via which the fuel discharged from the merge and discharge
unit 7 is returned to the fuel tank 2. Herein, the fuel of the
engine 3 that returns to the merge and discharge unit 7 by way of
the first fuel return route 12 is an amount commensurate with the
surplus with respect to the amount that is required in the engine
3, and would be, for example, surplus fuel from the rail 3a and
injector 3b of the common-rail engine 3 as well as surplus fuel
from the supply pump 11.
[0069] The configuration of such description thus, by being
provided with the first fuel return route 12 and the second fuel
return route 13, makes it possible for the surplus fuel in the
engine 3 to be returned to the fuel tank 2 by way of the first fuel
return route 12, the merge and discharge unit 7, and the second
fuel return route 13. Further, by being provided with the merge and
discharge unit 7, the configuration also makes it possible to merge
one portion of the surplus fuel in the engine 3 with the fuel from
the fuel tank 2 and to circulate the resulting confluence for
supply to the engine 3, as well as to return to the fuel tank 2 a
remaining portion surplus fuel in the engine 3.
[0070] The merge and discharge unit 7 shall now be described.
[0071] As illustrated in FIG. 1, there are four flow paths that are
connected to the merge and discharge unit 7, namely, that of an
upstream site 4a further upstream than the merge and discharge unit
7 in the fuel supply route 4, that of the first fuel return route
12, that of a downstream site 4b further downstream than the merge
and discharge unit 7 in the fuel supply route 4, and that of the
second fuel return route 13.
[0072] The merge and discharge unit 7 accepts and merges fuel from
the upstream site 4a of the fuel supply route 4 and fuel from the
first fuel return route 12, and discharges the merged fuels to the
downstream site 4b of the fuel supply route 4 and to the second
fuel return route 13.
[0073] As illustrated in FIGS. 2 and 3, the merge and discharge
unit 7 is provided with: a reservoir unit 14 in which fuel can be
collected; a first merge unit 15 for merging into the reservoir
unit 14 the fuel from the upstream site 4a of the fuel supply route
4; a second merge unit 16 for merging into the reservoir unit 14
the fuel from the first fuel return route 12; a first discharge
unit 17 for discharging a portion of the fuel of the reservoir unit
14 into the downstream site 4b of the fuel supply route 4; and a
second discharge unit 18 for discharging a remaining portion of the
fuel of the reservoir unit 14 into the second fuel return route 13.
FIG. 2 is a front view of the merge and discharge unit 7, and FIG.
3 is a side view of the merge and discharge unit 7.
[0074] The merge and discharge unit 7 is configured by combining a
recessed member and a planar member, a hollow space in the shape of
a cuboid being formed in the interior thereof; the hollow space
serves as the reservoir unit 14. The reservoir unit 14 is formed in
a vertically long shape, of greater length in the vertical
direction, and is adapted to be capable of collecting enough to be
capable of ensuring a fuel flow rate required by the engine 3. A
hole part 19 for attachment is also provided to both lateral sides
of the reservoir unit 14; inserting and fastening a bolt to the
hole parts 19 for attachment enables attachment to a desired
location.
[0075] The first merge unit 15, the second merge unit 16, the first
discharge unit 17, and the second discharge unit 18 are all formed
in a cylindrical shape, a hollow space in the interior thereof
being in communication with the reservoir unit 14. Further, the
first merge unit 15, the second merge unit 16, and the first
discharge unit 17 are arranged at sites on the lower side of the
reservoir unit 14 (a lower end), and the second discharge unit 18
is arranged at a site on the upper side of the reservoir unit 14
(an upper end). This gives a configuration such that air that is
included in the fuel rises to the site on the upper side of the
reservoir unit 14 and is discharged from the second discharge unit
18. Thus, though air may be included in the fuel being supplied to
the engine 3, it is accordingly possible to remove air in the merge
and discharge unit 7.
[0076] Holes in the cylindrical sites of the first merge unit 15,
the second merge unit 16, and the first discharge unit 17 are
formed at a first hole diameter, and a hole in the cylindrical site
of the second discharge unit 18 is formed to a second hole diameter
that is smaller than the first hole diameter. The second discharge
unit 18 is thereby provided with a constricted site where the flow
path cross-sectional area is smaller than that of the first
discharge unit 17, and providing the constricted site of such
description gives a configuration such that the amount of fuel
discharged from the second discharge unit 18 is less than the
amount of fuel discharged from the first discharge unit 17.
[0077] Herein, adjusting the extent to which the second hole
diameter is smaller than the first hole diameter makes it possible
to adjust the extent to which the amount of fuel discharged from
the second discharge unit 18 is less than the amount of fuel
discharged from the first discharge unit 17. Thus, merely the
simple adjustment of adjusting the hole diameter makes it possible
to adjust the magnitude of flow rates for the amount of fuel being
supplied to the engine 3 from the merge and discharge unit 7 and
for the amount of fuel being returned to the fuel tank 2 from the
merge and discharge unit 7.
[0078] The flow of fuel in the fuel supply device 1 shall now be
described.
[0079] As illustrated in FIG. 1, the fuel of the fuel tank 2 is
supplied to the engine 3 by way of the fuel supply route 4, and
surplus fuel in the engine 3 is returned to the merge and discharge
unit 7 of the fuel supply route 4 by way of the first fuel return
route 12. Then, in the merge and discharge unit 7, the surplus fuel
in the engine 3 is supplied by the second merge unit 16 to the
reservoir unit 14 and the fuel of the fuel tank 2 is supplied by
the first merge unit 15 to the reservoir unit 14, the surplus fuel
and the fuel being merged together and collected in the reservoir
unit 14. The fuel collected in the reservoir unit 14 is discharged
from both the first discharge unit 17 and the second discharge unit
18. Thereby, in the merge and discharge unit 7, the fuel from the
fuel tank 2 supplied by the upstream site 4a of the fuel supply
route 4 is merged into the surplus fuel having been returned by the
first fuel return route 12; a portion of the merged fuel is
supplied to the engine 3 by the downstream site 4b of the fuel
supply route 4, and a remaining portion of the fuel is returned to
the fuel tank 2 by the second fuel return route 13.
[0080] Thus, merely by providing the merge and discharge unit 7 to
a site between the fuel tank 2 and the filter 10 in the fuel supply
route 4 makes it possible to merge the surplus fuel in the engine 3
into the fuel from the fuel tank 2 and supply the merged fuels to
the filter 10. Even at such times as the initial start-up of the
engine 3 in a cold climate, it is accordingly possible to merge
fuel that has been heated by heat generated from the engine 3 or
the like into the low-temperature fuel from the fuel tank 2 and
supply comparatively high-temperature fuel to the filter 10, thus
making it possible to prevent clogging of the filter 10.
[0081] Because the fuel flow rate that is supplied to the merge and
discharge unit 7 by the upstream site 4a of the fuel supply route 4
is an amount corresponding to the fuel flow rate that is returned
to the fuel tank 2 from the merge and discharge unit 7, causing the
amount of fuel discharged from the second discharge unit 18 to be
less than the amount of fuel discharged from the first discharge
unit 17 in the merge and discharge unit 7 makes it possible to also
lessen the fuel flow rate being supplied to the merge and discharge
unit 7 from the fuel tank 2. It is accordingly possible to properly
increase the fuel temperature of the fuel being supplied to the
filter 10, and possible to reliably prevent clogging of the filter
10.
[0082] Also, because the amount of fuel being supplied to the merge
and discharge unit 7 from the upstream site 4a of the fuel supply
route 4 can be lessened, the flow rate intended to be processed by
the moisture removal unit 5 can be lessened, making it possible to
reduce the processing capability required for the moisture removal
unit 5, and also the required capacity for the electromagnetic pump
6 can be reduced. It is accordingly possible to successfully lower
the sizes and costs of the moisture removal unit 5 and the
electromagnetic pump 6.
[0083] The fuel that is returned to the merge and discharge unit 7
by way of the first fuel return route 12 is surplus fuel in the
engine 3, and this surplus fuel is supplied in circulation to the
engine 3, and thus there is the possibility that when the engine 3
is continuously operated, the fuel temperature of the fuel being
supplied to the engine 3 may gradually rise and reach an
excessively high level. In view whereof, because in the fuel supply
route 4 the cooling unit 8 is arranged further downstream than the
merge and discharge unit 7 in the fuel supply direction, the fuel
that is discharged from the merge and discharge unit 7 to the
downstream site 4b of the fuel supply route 4 can be cooled to a
desired temperature range by the cooling unit 8, thus preventing
the fuel temperature of the fuel being supplied to the engine 3
from reaching an excessively high level.
[0084] The fuel supply device 1 of the engine in the present
embodiment is adapted for a work vehicle such as a tractor 100, as
is illustrated in FIG. 4. The tractor 100 is of a four-wheel drive
format, provided with a traveling vehicle body 103 having a pair of
left and right front wheels 101 that can be driven and operated by
steering and a pair of left and right rear wheels 102 that can be
driven. A hood 104 in which the engine 3 and the like are housed is
provided to the front of the traveling vehicle body 103, and a
cabin 107 on which a steering handle 105, seat 106, and the like
are housed is provided to the rear of the traveling vehicle body
103.
[0085] A main frame 108 extends forward from a lower part of the
engine 3, and an axle case (not shown) onto which the front wheels
101 are mounted and the like are supported at the main frame 108. A
clutch housing 109 extends rearward from the engine 3, and a
transmission case 110 located below the seat 106 is coupled to the
clutch housing 109, the configuration being such that the power
from the engine 3 is transmitted to the rear wheels 102.
[0086] Provided to the rear of the traveling vehicle body 103 are a
link mechanism 111, constituted of a pair of left and right lift
arms, and a power take-off shaft 112. Such is the configuration
that coupling a rotary tilling device (not shown) or the like to
the link mechanism 111 so as to be vertically operable and
interlockingly coupling the rotary tilling device or the like to
the power take-off shaft 112 makes it possible to vertically
operate and drive the rotary tilling device or the like.
[0087] In the fuel supply device 1, as illustrated in FIG. 5,
housed within the hood 104 are the moisture removal unit 5, the
electromagnetic pump 6, the merge and discharge unit 7, the cooling
unit 8, the feed pump 9, the filter 10, and the supply pump 11.
[0088] FIG. 5 is a side view in which the interior of the hood 104
is viewed from the right side; the moisture removal unit 5, the
electromagnetic pump 6, the merge and discharge unit 7, the feed
pump 9, the filter 10, and the supply pump 11 are arranged on the
right side of the engine 3.
[0089] As illustrated in FIG. 4, the fuel tank 2 is arranged below
a floor panel 113 that forms the floor of the cabin 107. Although
not shown in the drawings, the fuel tank 2 is provided as a
left/right pair, with a first fuel tank arranged on the right side
of the cabin 107 and a second fuel tank arranged on the left side
thereof. A fuel replenishment port is provided to the first fuel
tank, the configuration being such that fuel is supplied from the
first fuel tank to the second fuel tank by way of an
interconnecting path. Intake of the fuel from the fuel tank 2
involves taking in fuel from the second fuel tank and supplying the
taken-in fuel to the engine 3 by the fuel supply route 4.
[0090] As illustrated in FIG. 5, the merge and discharge unit 7 is
fixed to the support member 114 by the bolt being inserted and
fastened to the hole part 19 for attachment, and the position for
arranging same is a position high up on the right side than the
engine 3. This makes it possible for the position for arranging the
merge and discharge unit 7 to be a high position, thus making it
possible, even when air is included in the fuel collected in the
reservoir unit 14, for the air to rise and be discharged from the
second discharge unit 18, allowing for proper removal of air in the
merge and discharge unit 7. In regard thereto, the height at which
the merge and discharge unit 7 is arranged is a position that is
higher than those of the moisture removal unit 5, the
electromagnetic pump 6, the feed pump 9, the filter 10, the supply
pump 11, and the like.
Other Embodiments
[0091] (1) In the foregoing embodiment, for example, arranging the
fuel tank 2 farther up than the moisture removal unit 5, the
cooling unit 8, or the like makes it possible to forgo the
electromagnetic pump 6 (which is equivalent to a second fuel pump).
Also, beyond the electromagnetic pump 6, it would furthermore be
possible to forgo the cooling unit 8 or the feed pump 9; of these
three devices, any one or two can be forgone, or all.
[0092] (2) In the foregoing embodiment, it would also be possible
for the position where the merge and discharge unit 7 is arranged
in the fuel supply route 4 to be located between the moisture
removal unit 5 and the electromagnetic pump 6.
[0093] (3) In the foregoing embodiment, causing the flow path
cross-sectional area of the second fuel return route 13 to be
smaller than that of the downstream site 4b in fuel supply route 4
makes it possible to provide to the second fuel return route 13 a
constricted site of lesser flow path cross-sectional area than that
of the downstream site 4b in the fuel supply route 4. Providing the
constricted part of such description also makes such a
configuration possible that the amount of fuel discharged from the
second discharge unit 18 is less than the amount of fuel discharged
from the first discharge unit 17.
[0094] Also, as regards the constricted site, there is no
restriction to being one where the flow path cross-sectional area
is adjusted; providing a constriction such as an orifice would also
make it possible to provide a constricted site.
[0095] (4) In the foregoing embodiment, the full amount of surplus
fuel of the engine 3 was returned to the merge and discharge unit 7
by the first fuel return route 12, but it would also be possible to
provide, for example, a connecting flow path for fuel return that
connects together the fuel tank 2 and a midway site of the first
fuel return route 12, so that a portion of the surplus fuel of the
engine 3 is returned to the merge and discharge unit 7 by the first
fuel return route 12 and a portion of the remaining surplus fuel of
the engine 3 is returned directly to the fuel tank 2 by the
connecting flow path for fuel return.
[0096] (5) The foregoing embodiment illustrates an example where
the fuel supply device for an engine as in the present invention is
adapted to the tractor 100 for agricultural use, but adaptation to
a variety of other work vehicles would also be possible.
Second Embodiment
[0097] An example where an intake structure for a fuel tank as in
the present invention has been adapted to a tractor shall now be
described, on the basis of the accompanying drawings.
[0098] This tractor 201, as illustrated in FIG. 6, is constituted
of a four-wheel drive format, provided with a traveling vehicle
body 204 having a pair of left and right front wheels 202 that can
be driven and operated by steering and a pair of left and right
rear wheels 203 that can be driven. A hood 206 in which an engine
205 and the like are housed is provided to the front of the
traveling vehicle body 204, and a cabin 209 on which a steering
handle 207, a seat 208, and the like are housed is provided to the
rear of the traveling vehicle body 204.
[0099] A main frame 210 extends forward from a lower part of the
engine 205, and an axle case (not shown) onto which the front
wheels 202 are mounted and the like are supported at the main frame
210. A clutch housing 211 extends rearward from the engine 205, and
a transmission case 212 located below the seat 208 is coupled to
the clutch housing 211, the configuration being such that the power
from the engine 205 is transmitted to the rear wheels 203.
[0100] Provided to the rear of the traveling vehicle body 204 are a
link mechanism 213, constituted of a pair of left and right lift
arms, and a power take-off shaft 214. Such is the configuration
that coupling a rotary tilling device (not shown) or the like to
the link mechanism 213 so as to be vertically operable and
interlockingly coupling the rotary tilling device or the like to
the power take-off shaft 214 makes it possible to vertically
operate and drive the rotary tillage device or the like.
[0101] Housed within the transmission case 212 are, for example, a
gear-type transmission device and a stepless transmission device
such as a hydrostatic stepless transmission device, though a
depiction thereof has been forgone; power taken out from the engine
205 is transmitted to the stepless transmission device via a main
clutch (not shown) or the like. Of the power that is taken out from
the stepless transmission device, power for traveling is
transmitted to the left and right front wheels 202 and to the left
and right rear wheels 203 via the gear-type transmission device. Of
the power that is taken out from the stepless transmission device,
also, power for working is transmitted to the power take-off shaft
214 via an action clutch (not shown) or the like.
[0102] The cabin 209, as illustrated in FIGS. 6 and 7, is
configured to be provided with: a cabin frame 215; a front
windshield 216 for covering the front surface of the cabin frame
215; a door 217 provided to an entry on two sides of the cabin
frame 215; a side windshield 218 provided to the rear of the door
217; and a rear windshield 219 for covering the rear surface of the
cabin frame 215.
[0103] The cabin frame 215 is provided with: a support frame 22, in
the shape of a square pipe, for supporting the cabin 209; a lower
frame 221 coupled to the support frame 220; and an upper frame 222.
Between the lower frame 221 and the upper frame 222, a pair of left
and right A-posts 223 are provided to the front end thereof, a pair
of left and right B-posts 224 are provided to the middle thereof,
and a pair of left and right C-posts 225 are provided to the rear
end thereof. The A-posts 223, the B-posts 224, and the C-posts 225
are each coupled by the upper end to the upper frame 222 and by the
lower end to the lower frame 221.
[0104] The lower side of the cabin frame 215 is equipped with a
floor panel 226 that forms the floor of the cabin 209, and a rear
wheel fender 227 formed in a shape that covers the outer periphery
of the rear wheels 203 from above is fixed to both left and right
sides of the floor panel 226. The floor panel 226 is configured to
be provided with a step floor panel 226a for the front of the cabin
209 and a seat floor panel 226b for the rear of the cabin 209, the
seat 208 being disposed at the left/right middle of the seat floor
panel 226b.
[0105] The steering handle 207, as illustrated in FIG. 7, is
supported at the front of the cabin 209. The front windshield 216
is mounted across the left and right A-posts 223, and the front
surface of the cabin frame 215 is covered by the front windshield
216. The rear windshield 219 is mounted across the left and right
C-posts 225, and the rear surface of the cabin frame 215 is covered
by the rear windshield 219. The doors 217 are mounted onto the
entries on both sides of the cabin frame 215 formed across the
A-posts 223 and the B-posts 224, so that the doors can be slid open
about an axis of the rear end; the side windshields 218 are mounted
across the B-posts 224 and the C-posts 225 so that the side
windshields can be slid open.
[0106] Fuel tanks 228 for collecting fuel to be supplied to the
engine 205, as illustrated in FIGS. 6 and 7, are arranged below the
step floor panel 226a in the floor panel 26 that forms the floor of
the cabin 209. The fuel tanks 228, as illustrated in FIG. 8, are
provided as a left/right pair, with a first fuel tank 228a arranged
on the right side of the cabin 209 and a second fuel tank 228b
arranged on the left side thereof. The first fuel tank 228a and the
second fuel tank 228b are each supported by the traveling vehicle
body 204 via a frontal support bracket 231 provided to a frontal
site thereof and via a rear support bracket 232 provided to a rear
site thereof.
[0107] A fuel replenishment unit 229 is provided to the first fuel
tank 228a, and a communicating part that interconnects the first
fuel tank 228a and the second fuel tank 228b is provided. Fuel
being replenished from the fuel replenishment unit 229 is thereby
supplied to the first fuel tank 228a, passed through the
communicating part 230 from the first fuel tank 228a, and supplied
also to the second fuel tank 228b. The communicating part 230 is
provided with a check valve (not shown) that allows fuel to flow
through from the first fuel tank 228a to the second fuel tank 228b
and checks against flow of fuel through from the second fuel tank
228b to the first fuel tank 228a. The communicating part 230 is
covered by a cover body 233, of concave cross-section, that covers
the front side thereof, the rear side thereof, and the bottom side
thereof.
[0108] The first fuel tank 228a and the second fuel tank 228b are
constituted of a resin that has been molded by blow molding. The
first fuel tank 228a and the second fuel tank 228b are provided
with a stepped part so as to be of different height at the upper
end thereof, and are formed in a shape that is longer in the
front/rear direction when seen in plan view. The first fuel tank
228a and the second fuel tank 228b, as illustrated in FIGS. 7 and
8, are formed in a curved shape so that an outside site of the rear
end site thereof runs along the shape of the front end site of the
rear wheel fender 227, as seen in plan view, and the rear end site
thereof is configured so as to extend further rearward than the
front end of the rear wheel fender 227. The first fuel tank 228a
and the second fuel tank 228b are thus adapted to be capable of
ensure a greater capacity while also making effective use of the
space below the step floor panel 226a.
[0109] In the present embodiment, an intake structure 300 for a
fuel tank is provided to the second fuel tank 228b, the
configuration being such that fuel that has been taken in by the
intake structure 300 is supplied to the engine 205 by way of a fuel
supply route 234. A fuel return route 235 for returning to the fuel
tanks 228 fuel from the engine 205 is connected to the first fuel
tank 228a.
[0110] The following describes the intake structure 300.
[0111] The intake structure 300, as illustrated in FIG. 9, is
provided with: an intake unit 301 for taking in and drawing out
fuel N of the second fuel tank 228b, above the bottom of the second
fuel tank 228b; a recessed reservoir unit 302 that is arranged at
the bottom of the second fuel tank 228b, is recessed so as to be
lower than same, and is able to collect the fuel N; and a covering
303 for covering the recessed reservoir unit 302 in a state where
the fuel N is permitted to flow into the recessed reservoir unit
302. The intake unit 301 is adapted to take in and draw out the
fuel N that has been collected in the recessed reservoir unit
302.
[0112] FIG. 9 is a cross-sectional view in which the second fuel
tank 228b is seen from the rear in FIG. 10; as illustrated in FIG.
9, the second fuel tank 228b is formed in a shape where an upper
site 228A of the outside thereof is projected outward, and the
bottom thereof is formed so as to be stepped, having a stepped part
228D between an outer bottom 228B and an inner bottom 228C.
[0113] The recessed reservoir unit 302 is provided to the inner
bottom 228C, which is located bottommost on the bottom of the
second fuel tank 228b. The recessed reservoir unit 302 is arranged
at a position close to the stepped part 228D on the inner bottom
228C, and is arranged at a position where the fuel N readily flows
in at the curved stepped part 228D. The recessed reservoir unit
302, as illustrated in FIG. 10, is formed in a circular shape when
seen in plan view, and an inner wall part 302a thereof is formed in
an inclined shape, where a lower site is located further inward
than is an upper site.
[0114] The covering 303, as illustrated in FIGS. 9 and 10, is
constituted of a circular cylindrical body 303a having a hollow
space that has communication with the recessed reservoir unit 302,
and the lower end of the cylindrical body 303a is formed so as to
be smaller than the recessed reservoir unit 302 when seen in plan
view and is inserted into the interior of the recessed reservoir
unit 302. Because the recessed reservoir unit 302 and the covering
303 are both formed so as to be circular, the outer diameter of the
covering 303 is configured so as to be smaller than the inner
diameter of the recessed reservoir unit 302. The covering 303 is
arranged at a middle site of the recessed reservoir unit 302 when
seen in plan view, the configuration being such that the middle
site of the recessed reservoir unit 302 is covered by the covering
303.
[0115] This manner of arranging the covering 303 makes it possible
to form a spacing K1 between an outer wall part of the covering 303
and the inner wall part 302a of the recessed reservoir unit 302,
across the full length of the outer periphery of the covering 303.
Accordingly, covering the middle site of the recessed reservoir
unit 302, as seen in plan view, with the covering 303, while also
allowing the fuel N to flow into the recessed reservoir unit 302
from the spacing K1, prevents the fuel N from flowing outwardly
from the recessed reservoir unit 302.
[0116] The covering 303 is configured to be provided with the
circular cylindrical body 303a, the interior of which is a hollow
space, and is arranged so that the lower end of the cylindrical
body 303a extends out to the interior of the recessed reservoir
unit 302. Thus, even when the traveling vehicle body 204 is swung
in the front/rear direction and the left/rear direction, the
presence of the cylindrical body 303a prevents the liquid level of
the fuel N that has been collected in the recessed reservoir unit
302 from swinging. Moreover, as illustrated in FIG. 9, the fuel N
can be collected in the hollow space of the interior of the
cylindrical body 303a, as well, and a correspondingly greater
capacity of fuel taken in by the intake unit 301 can be ensured. It
is thus possible for the fuel N having been collected in the
recessed reservoir unit 302 to flow out therefrom, while a greater
capacity of fuel N taken in by the intake unit 301 can also be
ensured; an event where no fuel N remains in the lower end of the
intake unit 301 and where air is taken in at the intake unit 301
can be properly prevented.
[0117] The intake unit 301 is constituted of a tubular body
supported by the covering 303, and is disposed extending upward and
downward through the interior space of the hollow of the covering
303. The lower end of the intake unit 301 is given substantially
the same height as the lower end of the covering 303, and is
inserted into the interior of the recessed reservoir unit 302. The
intake unit 301 is arranged at a position shifted further toward
the outer periphery than the middle, as seen in plan view, in the
circular cylindrical body 303a in the covering 303.
[0118] Herein, for example, the lower ends of the intake unit 301
and of the covering 303 are arranged at a vertically intermediate
part of the recessed reservoir unit 302. The spacing K1 between the
outer wall part of the covering 303 and the inner wall part 302a of
the recessed reservoir unit 302 is configured so as to be smaller
than a spacing K2 that is between the bottom of the recessed
reservoir unit 302 and the lower ends of the intake unit 301 and of
the covering 303.
[0119] This makes it possible to properly prevent the collected
fuel N from flowing outwardly therefrom, while also making it
possible to collect even more of the fuel N.
[0120] The covering 303, as has been described above, is
constituted of the circular cylindrical body 303a, but is provided
with a cover body 303b for closing off an upper part of the
cylindrical body 303a. The cover body 303b is configured to be of a
disc shape of greater diameter than that of the cylindrical body
303a, and a site projecting further outward than the cylindrical
body 303a serves as an attachment site for the second fuel tank
228b. A circular opening part permitting insertion and removal of
the cylindrical body 303a is formed at the upper surface of the
second fuel tank 22b, the configuration being such that the
covering 303 is mounted onto the second fuel tank 228b by inserting
and fastening a bolt to a hole part of the attachment site of the
cover body 303b in a state where the cylindrical body 303a has been
inserted into the opening part. The intake unit 301 is supported by
the covering 303 in a state of penetrating through the cover body
303b, and is adapted to enable insertion and removal of the cover
body 303 supporting the intake unit 301, into/from the second fuel
tank 228b.
[0121] Provided to an upper site of the cylindrical body 303a are a
plurality of communicating holes 304 creating communication between
a hollow space of the interior thereof and the exterior thereof.
The plurality of communicating holes 304 are arranged dispersed in
the peripheral direction and up/down direction of the cylindrical
body 303a. This gives such a configuration that even when air is
included in the fuel N that is collected in the recessed reservoir
unit 302, the air rises through the hollow space of the cylindrical
body 303a and is discharged to the exterior of the cylindrical body
303a at the communicating holes 304. Also provided to the cover
body 303b is an exterior communicating part 305 that penetrates
therethrough and creates communication between the hollow space of
the interior of the cylindrical body 303a and the exterior of the
second fuel tank 228b. The exterior communicating part 305 is
adapted to discharge to the exterior of the second fuel tank 228b
air that has risen through the hollow space. The communicating
holes 304 and the exterior communicating part 305 are thus provided
to the upper site of the cylindrical body 303a, as an air discharge
unit capable of discharging the air of the hollow space to the
exterior of the cylindrical body 303a. Thus, even when air is
included in the fuel N having been collected in the recessed
reservoir unit 302, it is possible to properly remove the air, and
more reliably prevent the air from being taken in at the intake
unit 301.
[0122] Coupling of a front loader to the front of the traveling
vehicle body 204, though a depiction thereof has been omitted,
enables the tractor 201 configured in this manner to, for example,
carry out work such excavating earth and sand or transporting and
transferring the earth and sand to a desired location such as a
track, and the like. In addition to a rotary tilling device that
can be interlockingly coupled to the power take-off shaft 214, the
configuration also permits mounting of a variety of other work
devices, depending on the work, to the rear of the traveling
vehicle body 204. Also, though a depiction has been omitted, a
plurality (for example, three) of auxiliary control valves are
provided to the rear of the traveling vehicle body 204, in the
vicinity of a hydraulic device of the link mechanism 213 or the
like, and therefore in cases where a variety of work devices are
mounted the configuration makes it possible to couple hydraulic
control machinery for the work device to the auxiliary control
valves and hydraulically control the work device.
[0123] The tractor 201 is thus adapted to be capable of carrying
out a variety of tasks, by coupling the front loader to the front
of the traveling vehicle body 204 or by coupling a variety of work
devices to the rear of the traveling vehicle body 204. Also
provided inside the cabin 209 are a variety of operation levers,
such as an operation lever for causing the traveling vehicle body
204 to travel, as well as an operation lever for manually operating
the front loader and an operation lever for manually operating the
work devices.
[0124] A variety of operation levers disposed inside the cabin 209
shall now be described.
[0125] As illustrated in FIGS. 7 and 11, a variety of operation
levers are disposed in concentration above the rear wheel fender
227 on the right side of the seat 208. FIG. 11 is a perspective
view illustrating the right side of the seat 208 of the cabin 209.
Provided as operation levers are: a hand accelerator lever 236 for
manually operating the accelerator; a loader lever 237 for the
front loader; a draft lever 238 for setting a work load in a draft
control for maintaining a constant work load; a position lever 239
for carrying out positional control vertically moving the link
mechanism 213; and auxiliary control levers 240, 241, 242 for
operating the auxiliary control valves. As regards the auxiliary
control levers, three auxiliary control valves are provided to the
rear of the traveling vehicle body 204, as is described above, and
thus there are three operating levers provided, namely, a first
auxiliary control lever 240, a second auxiliary control lever 241,
and a third auxiliary control lever 242.
[0126] Also, in addition to the variety of operation levers 236 to
242, a power take-off switch 243 for switching the power take-off
shaft 214 between a drive state and a non-drive state is also
disposed on the right side of the seat 208.
[0127] The following describes the arrangement positions,
configurations, and the like of the variety of operation levers 236
to 242. The "left/right direction" is understood to be the
left/right direction of the traveling vehicle body 204 (the X
direction in FIGS. 7 and 11), and the "front/rear direction" is
understood to be the front/rear direction of the traveling vehicle
body 204 (the Y direction in FIGS. 7 and 11).
[0128] Among the variety of operation levers, the hand accelerator
lever 236 is arranged at a position closest to the seat 208 in the
left/right direction (the X direction). A first installation
surface 244 for installing the hand accelerator lever 236 is formed
atop the rear wheel fender 227. The first installation surface 244
is formed in an inclined shape that extends in the front/rear
direction (the Y direction) and becomes increasingly lower going
forward. The hand accelerator lever 236 is provided so as to be
able to swing forward and back along a first guide 245 extending in
the front/rear direction (the Y direction), formed on the first
installation surface 244.
[0129] The loader lever 237 is arranged further forward than the
hand accelerator lever 236, on the side further apart from the seat
208 than the hand accelerator lever 236 in the left/right direction
(the X direction). The loader lever 237 is configured in a
vertically oriented cross-shape permitting swinging in the
front/rear direction (the Y direction) and the left/right direction
(the X direction). The loader lever 237 is arranged so that a
rearward region of the swing range in the front/rear direction (the
Y direction) thereof is lined up in the left/right direction (the X
direction) with a forward region of the swing range in the
front/rear direction (the Y direction) of the hand accelerator
lever 236.
[0130] The draft lever 238 and the position lever 239 are both
arranged, in a state where the two levers are lined up together in
the left/right direction (the X direction), further rearward than
the loader lever 237, on a side further apart from the seat 208
than the hand accelerator lever 236 in the left/right direction
(the X direction). A second installation surface 246 for installing
the draft lever 238 and the position lever 239 is formed atop the
rear wheel fender 227, and the second installation surface 246 is
adapted so as to be one step higher than the first installation
surface 244. A second guide 247 and a third guide 248 that are
further inclined at the front side toward the side that is apart
from the seat 208 in the left/right direction (the X direction) are
formed on the second installation surface 246, and the draft lever
238 and the position lever 239 are provided so as to be able to
swing along the second guide 247 and the third guide 248.
[0131] The power take-off switch 243 is arranged on the rear side
of the hand accelerator lever 236. A third installation surface 249
for installing the power take-off switch 243 is formed. The third
installation surface 249 is formed in a curved shape that is lower
than the first installation surface 244 and extends in the
front/rear direction, and the power take-off switch 243 is provided
to the third installation surface 249 and adapted to be
press-operable.
[0132] The auxiliary control levers 240 to 242 are arranged further
rearward than the draft lever 238 and the position lever 239, on a
side that is further apart from the seat 208 than the draft lever
238, the position lever 239, and the power take-off switch 243 in
the left/right direction (the X direction). A fourth installation
surface 250 for installing the first auxiliary control lever 240
and the second auxiliary control lever 241 is formed, and a fifth
installation surface 251 for installing the third auxiliary control
lever 242 is formed. The fourth installation surface 250 is
provided with a stepped part relative to the rear end of the second
installation surface 246, and is formed at a higher position than
that of the second installation surface 246 in an inclined shape
that becomes lower going forward. A fourth guide 252 and a fifth
guide 253 extending in the front/rear direction (the Y direction)
are formed on the fourth installation surface 250 in a state of
being lined up together in the left/right direction (the X
direction), and the first auxiliary control lever 240 and the
second auxiliary control lever 241 are provided so as to be able to
slide along the fourth guide 252 and the fifth guide 253. The fifth
installation surface 251 is a rearward continuation from the fourth
installation surface 250, and is formed in an inclined shape that
becomes lower going rearward. A sixth guide 254 that extends in the
front/rear direction (Y direction) is formed on the fifth
installation surface 251, and the third auxiliary control lever 242
is provided so as to be able to slide along the sixth guide
254.
[0133] As regards the arrangement relationship of the three
operation levers, i.e., the first through third auxiliary control
levers 240 to 242, the first auxiliary control lever 240 and the
second auxiliary control lever 241 are lined up together in the
left/right direction (the X direction), and the third auxiliary
control lever 242 is arranged further rearward than the first
auxiliary control lever 240 and the second auxiliary control lever
241 on a side that is further apart from the seat 208 than the
first auxiliary control lever 240 and the second auxiliary control
lever 241 in the left/right direction (the X direction). In other
words, the arrangement positions of the three operation levers,
i.e., the first through third auxiliary control levers 240 to 242,
are arranged so as to be in an L-shape when seen in plan view.
[0134] This manner of arranging the first through third auxiliary
control levers 240 to 242 prevents the third auxiliary control
lever 242 from becoming a hindrance when the driver operates the
first auxiliary control lever 240 or the second auxiliary control
lever 241, and conversely also prevents the first auxiliary control
lever 240 or the second auxiliary control lever 241 from becoming a
hindrance when the driver operates the third auxiliary control
lever 242. Also, for example, there is no need to ensure adequate
installation space for lining up the three operation levers
together in the left/right direction (the X direction), and this is
beneficial in terms of installation space. Moreover, because a
comparatively greater left/right (X-direction) spacing is taken
between the first auxiliary control lever 240 and the second
auxiliary control lever 241, the second auxiliary control lever 241
is less likely to become a hindrance when the driver operates the
first auxiliary control lever 240 and the first auxiliary control
lever 240 is less likely to become a hindrance when the driver
operates the second auxiliary control lever 241.
Accordingly, the operability of the auxiliary control levers 240 to
242 can be enhanced.
[0135] The first and second auxiliary control levers 240, 241 are
pivotally supported at proximal ends thereof, as illustrated in
FIG. 12, and are provided with a proximal end side 256 extending
from a pivot support 255 therefor and a distal end site 257 curved
upward from the proximal end site 256. The first and second
auxiliary control levers 240, 241 are thereby adapted to have a
large swing range in not only the front/rear direction but also in
the up/down direction. The fifth installation surface 251, which is
formed in an inclined shape that becomes lower going rearward, is
present at the rear side of the first and second auxiliary control
levers 240, 241. Therefore, the driver is readily able to
vertically swing the first and second auxiliary control levers 240,
241 in a state where the wrist or the like is placed atop the fifth
installation surface 251. The operability of the first and second
auxiliary control levers 240, 241 can accordingly be even further
enhanced.
Other Embodiments
[0136] (1) In the foregoing embodiment, the covering 303 was
constituted of the cylindrical body 303a, but, for example, as
illustrated in FIGS. 13 and 14, the covering 303 could also be
constituted of a planar body. In such a case, as illustrated in
FIGS. 13 and 14, supporting the covering 303 on the intake unit 301
makes it possible to arrange the covering 303 at a desired
location.
[0137] In FIG. 13, the planar body that is the covering 303 is
formed in a circular shape of lesser diameter than that of the
circular recessed reservoir unit 302, and is arranged so that a
middle site of the recessed reservoir unit 302 as seen in plan view
is covered with the covering 303. Also, in FIG. 13, the covering
303 is inserted into the interior of the recessed reservoir unit
302.
[0138] In FIG. 14, the planar body that is the covering 303 is
formed in a circular shape of greater diameter than that of the
circular recessed reservoir unit 302, and is arranged so that the
entirety of the recessed reservoir unit 302 as seen in plan view is
covered with the covering 303. Also, in FIG. 14, the covering 303,
spaced apart from the bottom of the fuel tanks, is arranged
thereabove.
[0139] (2) In the foregoing embodiment, the fuel tank 228 is
constituted of the first fuel tank 228a and the second fuel tank
228b, but, for example, a single fuel tank would also be possible,
and the number thereof can be altered as appropriate. Also, as
regards the arrangement positions of the fuel tanks 228, there is
no limitation to being below the step floor panel 226a; for
example, arrangement in the interior of the hood 206 would also be
possible, and the arrangement positions thereof can be altered as
appropriate.
[0140] (3) In the foregoing embodiment, the arrangement position of
the covering 303 can be altered as appropriate. As stated in (1)
above, as illustrated in FIG. 14, the entirety of the recessed
reservoir unit 302 as seen in plan view may be covered; in a case
where a portion of the recessed reservoir unit 302 as seen in plan
view is covered, there is no limitation to the middle site being
covered. Neither is the lower end of the covering 103 limited to
being inserted into the interior of the recessed reservoir unit
302; the lower end of the covering 103 can be arranged, e.g., so as
to become substantially flush with the bottom of the fuel
tanks.
[0141] (4) In the foregoing embodiment, an example where the intake
structure for a fuel tank as in the present invention is adapted to
the tractor 201 is illustrated, but the intake structure may be
adapted to a variety of other work vehicles is also possible.
* * * * *