# Patent

## Title
Oil storage tank and construction vehicle

## Abstract

An oil storage tank includes a hydraulic oil tank configured to store hydraulic oil, a fuel oil tank configured to store fuel oil, a breather valve disposed on the hydraulic oil tank, and a breather hose connected to the breather valve. The hydraulic oil tank includes a first facing face facing the fuel oil tank. The fuel oil tank includes a second facing face facing the hydraulic oil tank. The second facing face has a fuel-oil-tank adjacent face and a fuel-oil-tank sloped face. The fuel-oil-tank adjacent face extends along the hydraulic oil tank. The fuel-oil-tank sloped face is connected to the fuel-oil-tank adjacent face and slopes relative to the fuel-oil-tank adjacent face so as to be away from the hydraulic oil tank. The breather hose is disposed along the fuel-oil-tank sloped face.

## Background
CROSS REFERENCE TO RELATED APPLICATIONS
This is a divisional application of U.S. patent application Ser. No. 13/583,561, filed on Sep. 7, 2012, now pending. This application claims priority to Japanese Patent Application Nos. 2011-045618 and 2011-045619 filed on Mar. 2, 2011. The entire disclosures of U.S. patent application Ser. No. 13/583,561 Japanese Patent Application Nos. 2011-045618 and 2011-045619 are hereby incorporated herein by reference.


TECHNICAL FIELD
The present invention relates to an oil storage tank comprising a step, and to a construction vehicle comprising the oil storage tank.
BACKGROUND ART
Hydraulic excavators and other construction vehicles typically comprise a fuel oil tank for storing fuel oil, and a hydraulic oil tank for storing hydraulic oil. A technique is widely used in which the fuel oil tank and the hydraulic oil tank are integrally coupled to constitute an “oil storage tank,” whereby the rigidity of each of the two tanks is mutually improved.
There are known techniques for providing a breather valve to the upper face of the hydraulic oil tank in order to adjust the amount of air inside the hydraulic oil tank in accordance with the rise and fall of the fluid face the hydraulic oil (e.g., Japanese Laid-open Patent Application Nos. 2006-46016 and 2007-177501). However, with such techniques, gravel and/or dust are liable to penetrate the interior of the hydraulic oil tank via the breather valve. In view of the above, a technique has been proposed for attaching the breather hose to the breather valve and drawing the breather hose along the side face of the hydraulic oil tank (Japanese Laid-open Patent Application No. 2009-30346).
SUMMARY
Nevertheless, there is a problem with such a technique in that the space for drawing the breather hose around must be obtained in the vicinity of the hydraulic oil tank, and the space for disposing the oil storage tank overall increases.
The present invention was devised in view of the foregoing problems, it being an object thereof to provide an oil storage tank that can be reduced the space for disposing the oil storage tank, and to provide a construction vehicle comprising the oil storage tank.
The oil storage tank according to a first aspect of the present invention comprises: a hydraulic oil tank configured to store hydraulic oil; a fuel oil tank configured to store fuel oil; a breather valve disposed on the hydraulic oil tank; and a breather hose connected to the breather valve, the hydraulic oil tank including a first facing face facing the fuel oil tank; the fuel oil tank including a second facing face facing the hydraulic oil tank; the second facing face having a fuel-oil-tank adjacent face and a fuel-oil-tank sloped face, the fuel-oil-tank adjacent face extending along the hydraulic oil tank, and the fuel-oil-tank sloped face communicating with the fuel-oil-tank adjacent face and sloping relative to the fuel-oil-tank adjacent face so as to be away from the hydraulic oil tank; and the breather hose disposed along the fuel-oil-tank sloped face.
In accordance with the oil storage tank of the first aspect of the present invention, the breather hose can be accommodated along the fuel-oil-tank sloped face. Accordingly, there is no need to obtain space for drawing the breather hose around the periphery of the oil storage tank. As a result, the space for disposing the oil storage tank can be reduced.
The oil storage tank according to a second aspect of the present invention is the construction vehicle according to the first aspect, wherein the fuel-oil-tank sloped face communicates with an upper face and a lower face of the fuel oil tank.
In accordance with the second aspect of the present invention, the external shape of the oil storage tank can be made simpler than a case in which the fuel-oil-tank sloped face is discontinuous in the vertical direction. Accordingly, the cost of manufacturing the oil storage tank can be reduced.
The oil storage tank according to a third aspect of the present invention is the construction vehicle according to the first aspect, wherein the breather hose has a first end portion coupled to the breather valve, and a second end portion disposed lower than the oil storage tank.
In accordance with the oil storage tank of the third aspect of the present invention, it is possible to minimize soiling of the oil storage tank by the hydraulic oil contained in the air that flows from the second end portion.
The oil storage tank according to a fourth aspect of the present invention is the construction vehicle according to the first aspect, wherein the first facing face having a hydraulic-oil-tank adjacent face and a hydraulic-oil-tank sloped face, the hydraulic-oil-tank adjacent face extending along the fuel oil tank, and the hydraulic-oil-tank sloped face communicating with the hydraulic-oil-tank adjacent face and sloping relative to the hydraulic-oil-tank adjacent face so as to be away from the fuel oil tank; and the breather hose disposed between the fuel-oil-tank sloped face and the hydraulic-oil-tank sloped face.
In accordance with the oil storage tank of the fourth aspect of the present invention, space for accommodating the breather hose can be readily obtained.
The oil storage tank according to an fifth aspect of the present invention is the construction vehicle according to the first aspect, wherein the hydraulic oil tank is disposed on the vehicle-body-interior side of the fuel oil tank.
In accordance with the oil storage tank of the fifth aspect of the present invention, it is possible to minimize the possibility that the worker moving on the step will errantly take a misstep off the step.
The oil storage tank according to a sixth aspect of the present invention comprises: a hydraulic oil tank configured to store hydraulic oil; a fuel oil tank configured to store fuel oil; a breather valve disposed on the hydraulic oil tank; and a breather hose connected to the breather valve, the hydraulic oil tank including a first facing face facing the fuel oil tank; the fuel oil tank including a second facing face facing the hydraulic oil tank; the first facing face having a hydraulic-oil-tank adjacent face and a hydraulic-oil-tank sloped face, the hydraulic-oil-tank adjacent face extending along the fuel oil tank, and the hydraulic-oil-tank sloped face communicating with the hydraulic-oil-tank adjacent face and sloping relative to the hydraulic-oil-tank adjacent face so as to be away from the fuel oil tank; and the breather hose disposed along the hydraulic-oil-tank sloped face.
In accordance with the oil storage tank of the sixth aspect of the present invention, the breather hose can be accommodated along the hydraulic-oil-tank sloped face in the same manner as the oil storage tank according to the first aspect. Accordingly, there is no need to obtain space for drawing the breather hose around the periphery of the oil storage tank. As a result, the space in which the oil storage tank is disposed can be reduced.
The construction vehicle according to a seventh aspect of the present invention comprises: the oil storage tank recited in the first or sixth aspect; a working unit configured to receive supply of the hydraulic oil from the hydraulic oil tank; and an engine configured to receive supply of the fuel oil from the fuel oil tank.
The construction vehicle according to a eighth aspect of the present invention is the construction vehicle according to the seventh aspect, comprising a working unit configured to receive supply of the hydraulic oil from the hydraulic oil tank; and an engine configured to receive supply of the fuel oil from the fuel oil tank.
In accordance with the construction vehicle according to the eighth aspect of the present invention, it is possible to minimize damage (including melting) by heat released from the exhaust gas treatment device. As a result, it is possible to eliminate the need to separately provide a heat shield material for guarding the breather hose.
The construction vehicle according to a ninth aspect of the present invention is the construction vehicle according to the seventh aspect, wherein a rear end of the hydraulic oil tank is positioned further forward than a rear end of the fuel oil tank in the longitudinal direction.
In accordance with the construction vehicle of the ninth aspect of the present invention, space for disposing the exhaust gas treatment device is more readily obtained rearward of the hydraulic oil tank.
The construction vehicle according to a tenth aspect of the present invention is the construction vehicle according to the seventh aspect, wherein the oil storage tank includes a step disposed above the hydraulic oil tank.
In accordance with the construction vehicle of the tenth aspect of the present invention, the worker uses the step as a platform, whereby the work of fueling the oil storage tank and/or the movement on the oil storage tank are facilitated.
The construction vehicle according to a eleventh aspect of the present invention is the construction vehicle according to the tenth aspect, wherein an upper face of the step is lower than an upper face of the fuel oil tank in the vertical direction.
In accordance with the construction vehicle of the eleventh aspect of the present invention, a vertical difference is provided between the fuel oil tank upper face and the upper face of the step, whereby the vertical difference serves as a fence and it is possible to minimize missteps off the step by the worker.
The construction vehicle according to a twelfth aspect of the present invention is the construction vehicle according to the tenth aspect, wherein the hydraulic oil tank is disposed on the vehicle-body-interior side of the fuel oil tank.
In accordance with the construction vehicle of the twelfth aspect of the present invention, it is possible to minimize the possibility that the worker moving on the step will errantly take a misstep off the step.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the hydraulic excavator 100 according to the embodiment as seen from the rear upper right;
FIG. 2 is a perspective view of the hydraulic excavator 100 according to the embodiment as seen from the front upper right;
FIG. 3 is a perspective view showing the internal configuration of the hydraulic excavator 100 according to the second embodiment;
FIG. 4 is a plan view showing the internal configuration of the hydraulic excavator 100 according to the second embodiment;
FIG. 5 is a perspective view of the oil storage tank 200 according to the second embodiment as seen from the front upper left;
FIG. 6 is a perspective view of the oil storage tank 200 according to the second embodiment as seen from the front upper left;
FIG. 7 is a top view of the oil storage tank 200 according to the second embodiment as seen from above;
FIG. 8 is a front view showing the configuration of the breather hose according to the second embodiment;
FIG. 9 is a top view showing the configuration of the recessed section 221 according to the second embodiment;
FIG. 10 is a top view showing the configuration of the recessed section 221 according to the second embodiment;
FIG. 11 is a perspective view showing the configuration of the recessed section 221 according to the second embodiment;
FIG. 12 is a perspective view showing the configuration of the oil storage tank 200 according to the second embodiment; and
FIG. 13 is a top view showing the configuration of the recessed section 221 according to the second embodiment.



DESCRIPTION OF EMBODIMENTS
Next, embodiments of the present invention are described with reference to the drawings. Portions that are the same or similar in the description of the drawings below are given the same or similar reference numerals. However, the drawings are schematic in nature, and the dimensional ratios or other attributes may be different from the actual component. Therefore, specific dimensions and the like should be determined with consideration given to the descriptions below. Also, it is apparent that portions that mutually differ in dimensional relationship and/or ratio are included among the drawings.
Configuration of Construction Vehicle
The configuration of the construction vehicle according to the first embodiment will be described with reference to the drawings. In the present embodiment, a hydraulic excavator will be described as an example of a construction vehicle. FIG. 1 is a perspective view of the hydraulic excavator 100 according to the first embodiment as seen from the rear upper right. FIG. 2 is a perspective view of the hydraulic excavator 100 according to the first embodiment as seen from the front upper right.
The hydraulic excavator 100 comprises a lower travel body 10, a swivel platform 20, a counterweight 30, a machine compartment 40, an engine compartment 50, a working unit 60, a cab 70, and stairs 80.
The hydraulic excavator 100 according to the present embodiment is a so-called “hydraulic excavator with a small rear swivel radius (Japanese Industrial Standards definition (JIS A 8340-4)).”
The lower travel body 10 has a pair of crawler belts 11, 12 capable of mutually independent rotation. A pair of crawler belts 11, 12 is rotated, whereby the hydraulic excavator 100 moves left, right, forward, and backward.
The swivel platform 20 is swivelably supported on the lower travel body 10. The swivel platform 20 constitutes the vehicle body frame of the hydraulic excavator 100. The counterweight 30, the engine compartment 50, the machine compartment 40, the working unit 60, and the cab 70 are disposed on the swivel platform 20.
The counterweight 30 is disposed behind the engine compartment 50. The counterweight 30 is formed by placing, e.g., scrap iron and/or concrete, or the like in a box assembled from steel plates. The counterweight 30 is used for maintaining vehicle body balance during excavation work or the like.
The machine compartment 40 is disposed in front of the engine compartment 50. The machine compartment 40 accommodates a later-described oil storage tank 200 (see FIG. 3). A step 260 (an example of “step member”) is provided to the machine compartment 40, as shown in FIG. 2. The step 260 is a platform mounted by a worker when work such as fueling the oil storage tank 200 is performed. The configuration of the oil storage tank 200 is later described.
The engine compartment 50 is disposed behind the machine compartment 40. The engine compartment 50 accommodates an engine and/or an exhaust gas treatment device, and the like (not shown). A maintenance platform 50S is provided to the engine compartment 50, as shown in FIG. 2. The maintenance platform 50S is a platform mounted by a worker during maintenance inside the engine compartment 50.
The working unit 60 is attached to the swivel platform 20 in front of the machine compartment 40. The working unit 60 has a boom 61, an arm 62 attached to the distal end of the boom 61, a bucket 63 attached to the distal end of the arm 62, and a hydraulic hose 64. Hydraulic oil is fed to hydraulic cylinders 61a, 62a, 63a, whereby the boom 61, the arm 62, and the bucket 63 are driven. Hydraulic hoses 64 constitute oil channels for feeding hydraulic oil to the hydraulic cylinders 62a, 63a. The hydraulic hoses 64 are disposed in front of the step 260, as shown in FIG. 2.
The cab 70 is a driver's cabin in which the worker of the hydraulic excavator 100 rides. The cab 70 is provided in front of the engine compartment 50 and to the side of the working unit 60 so as to allow the worker to view the motions of the working unit 60.
The stairs 80 are disposed in front of the machine compartment 40. The stairs 80 are stairs that the worker ascends and descends during work for feeding fuel to the oil storage tank 200 and/or during maintenance inside the engine compartment 50. The stairs 80 have a first stair 81, a second stair 82, a third stair 83, and a fourth stair 84. The fourth stair 84 extends to the step 260.
Internal Configuration of Construction Vehicle
First, the internal configuration of the construction vehicle 100 according to the embodiment will be described with reference to the drawings. FIG. 3 is a perspective view showing the internal configuration of the hydraulic excavator 100 according to the embodiment. FIG. 4 is a plan view showing the internal configuration of the hydraulic excavator 100 according to the embodiment.
The oil storage tank 200 disposed on the swivel platform 20 is accommodated in the machine compartment 40. The oil storage tank 200 has a hydraulic oil tank 210 and a fuel oil tank 220. The hydraulic oil tank 210 is disposed further inward of the vehicle body than the fuel oil tank 220. The fuel oil tank 220 is disposed on the right end of the vehicle body. The specific configuration of the oil storage tank 200 is described later.
An engine 51 and an exhaust gas treatment device 52 are accommodated in the engine compartment 50. The engine 51 and the exhaust gas treatment device 52 are disposed on the swivel platform 20. The engine 51 generates power using the fuel oil fed from the fuel oil tank 220. The exhaust gas treatment device 52 is connected to the exhaust system of the engine 51 and scavenges particulate matter contained in the exhaust of the engine 51. The exhaust gas treatment device 52 is adjacent to the rear of the oil storage tank 200. The temperature of the exhaust gas treatment device 52 may rise to a high temperature (e.g., about 500° C.) during operations.
Here, in the embodiment, the hydraulic excavator 100 is a hydraulic excavator with a small rear swivel radius, and the space that can be obtained for the machine compartment 40 and the engine compartment 50 is therefore limited. On the other hand, space in which the exhaust gas treatment device 52 is disposed in the engine compartment 50 must be obtained. Accordingly, the engine compartment 50 is designed so as to encroach into the rear of machine compartment 40, as shown in FIG. 4. Specifically, the rear end of the hydraulic oil tank 210 is positioned further forward than the rear end of the fuel oil tank 220, and the exhaust gas treatment device 52 is rearwardly adjacent to the hydraulic oil tank 210.
Configuration of Oil Storage Tank
The configuration of the oil storage tank 200 according to the embodiment will be described with reference to the drawings. FIG. 5 is a perspective view of the oil storage tank according to the embodiment as seen from the front upper left. FIG. 6 is a perspective view of the main body of the oil storage tank according to the embodiment as seen from the front upper left. FIG. 7 is a top view of the oil storage tank according to the embodiment as seen from above. In FIGS. 12 and 13, the step 260 on the hydraulic oil tank 210 is omitted.
The oil storage tank 200 has a hydraulic oil tank 210, a fuel oil tank 220, a recessed section 221, a first coupling member 230, a second coupling member 240, a plurality of step support members 250, and a step 260.
In the embodiment, the hydraulic oil tank 210 and the fuel oil tank 220 are coupled together by the first coupling member 230 and the second coupling member 240. However, the hydraulic oil tank 210 and the fuel oil tank 220 are not required to be coupled to each other. The hydraulic oil tank 210 and the fuel oil tank 220 may be arranged adjacent to each other, in direct contact with each other, or set at a distance from each with a predetermined gap. A detailed configuration of the hydraulic oil tank 210 and the fuel oil tank 220 is later described.
The recessed section 221 is formed along the vertical direction in the front face of the oil storage tank 200, as shown in FIGS. 11 and 12. Specifically, the recessed section 221 is sandwiched by the hydraulic-oil-tank facing face 210e of the hydraulic oil tank 210 and the fuel-oil-tank sloped face 220e of the fuel oil tank 220, as shown in FIG. 7.
The first coupling member 230 and the second coupling member 240 couple the hydraulic oil tank 210 and the fuel oil tank 220 together. The first coupling member 230 is disposed in front of the oil storage tank 200. The second coupling member 240 is disposed behind the oil storage tank 200.
The plurality of step support members 250 are disposed on the hydraulic oil tank 210, as shown in FIG. 5. The plurality of step support members 250 support the step 260.
The step 260 is a platform that a worker mounts during work for refueling the oil storage tank 200 and/or performing maintenance inside the engine compartment 50. The step 260 is supported by the plurality of step support members 250. The step 260 has a placement face 260a on which the foot of the worker is placed. The placement face 260a is disposed below the upper face 220a of the fuel oil tank. A vertical difference is thereby provided between the placement face 260a and the upper face 220a. 
Detailed Configuration of Hydraulic Oil Tank
A detailed configuration of the hydraulic oil tank 210 is next described with reference to FIGS. 11 to 13.
The hydraulic oil tank 210 is secured to the top of the swivel platform 20, as shown in FIGS. 11 and 12. The hydraulic oil tank 210 stores hydraulic oil to be fed to the working unit 60.
The hydraulic oil tank 210 has a hydraulic oil tank upper face 210a, a hydraulic oil tank lower face 210b, a hydraulic oil tank front face 210c, a hydraulic oil tank rear face 210d, a hydraulic-oil-tank facing face 210e, a maintenance lid 211, a filter device 212, a breather valve 213, and a breather hose 214, as shown in FIGS. 12 and 13.
The hydraulic oil tank upper face 210a is positioned below the placement face 260a of a later-described step 260. The hydraulic oil tank lower face 210b is provided opposite from the hydraulic oil tank upper face 210a, and faces the swivel platform 20. The hydraulic oil tank front face 210c communicates with the hydraulic oil tank upper face 210a and the hydraulic oil tank lower face 210b. The hydraulic oil tank rear face 210d is provided opposite from the hydraulic oil tank front face 210c, and faces the exhaust gas treatment device 52. The hydraulic-oil-tank facing face 210e faces the fuel oil tank 220.
The maintenance lid 211 is detachably attached to the hydraulic oil tank upper face 210a. The maintenance lid 211 is detached, whereby a strainer disposed inside the hydraulic oil tank 210 can be replaced.
The filter device 212 is detachably attached to the hydraulic oil tank upper face 210a. The filter device 212 filters abrasion dust and the like that contaminates the hydraulic oil flowing to the hydraulic oil tank 210.
The breather valve 213 is disposed on the hydraulic oil tank 210 (on the maintenance lid 211 in the embodiment). The breather valve 213 adjusts the amount of air inside the hydraulic oil tank 210 in accordance with the rise and fall of the fluid face the hydraulic oil. In other words, air flows out from the hydraulic oil tank 210 via the breather valve 213 when the fluid face of the hydraulic oil rises, and air flows into the hydraulic oil tank 210 via the breather valve 213 when the fluid face of the hydraulic oil falls.
The breather hose 214 is a tube through which air flows into or out from the breather valve 213. FIG. 8 is a front view showing the configuration of the breather hose. The breather hose 214 is composed of a first end 214a, an accommodated portion 214b, and a second end portion 214c, as shown in FIG. 8. The first end 214a is connected to the breather valve 213 and is disposed above an upper face 210a of the hydraulic oil tank. The accommodated portion 214b extends to the first end 214a and is accommodated inside a later-described recessed section 221. The second end portion 214c extends to the accommodated portion 214b and is disposed near the lower end of the hydraulic oil tank 210. The accommodated portion 214b is secured to a hose-securing portion 23 of the swivel platform 20.
Detailed Configuration of Fuel Oil Tank
The fuel oil tank 220 is secured to the top of the swivel platform 20, as shown in FIGS. 11 and 12. The fuel oil tank 220 stores fuel oil to be fed to the engine 51.
The fuel oil tank 220 has a fuel oil tank front face 220d, a fuel oil tank upper face 220a, a fuel oil tank lower face 220b, a fuel oil tank rear face 220f, a fuel-oil-tank facing face 220E, and a fueling port 222, as shown in FIGS. 12 and 13.
The fuel oil tank upper face 220a is positioned above the placement face 260a of the later-described step 260. The fuel oil tank lower face 220b is provided opposite from the fuel oil tank upper face 220a and faces the swivel platform 20. The fuel oil tank lower face 220b is provided lower than the hydraulic oil tank lower face 210b in the vertical direction. The fuel oil tank front face 220d communicates with the fuel oil tank upper face 220a and the fuel oil tank lower face 220b. The fuel oil tank front face 220d is provided in the same position as the hydraulic oil tank front face 210c in the longitudinal direction. The fuel oil tank rear face 220f is provided opposite from the fuel oil tank front face 220d. The fuel oil tank rear face 220f is provided further rearward from the hydraulic oil tank rear face 210d in the longitudinal direction. The fuel-oil-tank sloped face 220E faces the hydraulic oil tank 210.
Here, the fuel-oil-tank facing face 220E has a fuel-oil-tank adjacent face 220c and a fuel-oil-tank sloped face 220e, as shown in FIGS. 12 and 13. The fuel-oil-tank adjacent face 220c is formed along the hydraulic oil tank 210, and is adjacent to and directly facing the hydraulic-oil-tank facing face 210e. The fuel-oil-tank sloped face 220e communicates to the front end of the fuel-oil-tank adjacent face 220c. The fuel-oil-tank sloped face 220e slopes relative to the fuel-oil-tank adjacent face 220c so as to be away from the hydraulic oil tank 210. In the embodiment, the fuel-oil-tank sloped face 220e slopes relative to the hydraulic-oil-tank adjacent face 210e. The fuel-oil-tank sloped face 220e communicates with the fuel oil tank upper face 220a and the fuel oil tank lower face 220b. 
Such a fuel-oil-tank sloped face 220e forms the recessed section 221 together with the above-described hydraulic-oil-tank facing face 210e. The breather hose 214 is disposed along the fuel-oil-tank sloped face 220e. 
The fueling port 222 is provided to the top of the fuel oil tank upper face 220a. Fuel oil is replenished from the fueling port 222.
Operation and Effect
(1) In the oil storage tank 200 according to the embodiment, the fuel oil tank 220 has a fuel-oil-tank facing face 220E that faces the hydraulic oil tank 210. The fuel-oil-tank facing face 220E includes a fuel-oil-tank sloped face 220e that slopes relative to the fuel-oil-tank adjacent face 220c so as to be away from the hydraulic oil tank 210. The breather hose 214 is disposed along the fuel-oil-tank sloped face 220e. 
In this manner, in accordance with the oil storage tank 200 of the embodiment, the breather hose 214 can be accommodated in along the fuel-oil-tank sloped face 220e. Accordingly, there is no need to obtain space for drawing the breather hose around the outer periphery of the oil storage tank. As a result, the space in which the oil storage tank 200 is disposed can be reduced.
(2) The fuel-oil-tank sloped face 220e according to the embodiment communicates with the fuel oil tank upper face 220a and the fuel oil tank lower face 220b. 
Therefore, the external shape of the oil storage tank 200 can be made simpler than a case in which the fuel-oil-tank sloped face 220e is discontinuous in the vertical direction. Accordingly, the cost of manufacturing the oil storage tank 200 can be reduced.
(3) The breather hose 214 according to the embodiment has a second end portion 214c. The second end portion 214c is disposed lower than the fuel oil tank 220.
Therefore, it is possible is minimize soiling of the oil storage tank 200 by the hydraulic oil contained in the air that flows from the second end portion 214c. 
(4) In the hydraulic excavator 100 (an example of a “construction vehicle”) according to the embodiment, the fuel-oil-tank sloped face 220e does not face the exhaust gas treatment device 52.
Therefore, it is possible to minimize damage (including melting) to the accommodated portion 214b of the breather hose 214 by heat released from the exhaust gas treatment device 52. As a result, it is possible to eliminate the need to separately provide a heat shield material for guarding the accommodated portion 214b. 
(5) In the hydraulic excavator 100 according to the embodiment, the rear end of the hydraulic oil tank 210 is position further forward than the rear end of the fuel oil tank 220.
Therefore, space for disposing the exhaust gas treatment device 52 is more readily obtained rearward of the hydraulic oil tank 210. This is an effective arrangement in the case that obtaining space for disposing the exhaust gas treatment device 52 is difficult such as with a hydraulic excavator with a small rear swivel radius.
(6) The hydraulic excavator 100 according to the embodiment comprises a step 260 disposed above the hydraulic oil tank 210.
Therefore, the worker uses the step 260 as a platform, whereby the work of fueling the oil storage tank 200 and/or the movement on the oil storage tank 200 are facilitated.
(7) The upper face of the step 260 according to the embodiment is lower than the fuel oil tank upper face 220a. 
In this manner, a vertical difference is provided between the fuel oil tank upper face 220a and the upper face of the step 260, whereby the vertical difference serves as a fence and it is possible to minimize missteps off the step 260 by the worker.
(8) In the hydraulic excavator 100 according to the embodiment, the hydraulic oil tank 210 is disposed further inward of the vehicle body than the fuel oil tank 220.
Therefore, it is possible to minimize the possibility that the worker moving on the step 260 will errantly take a misstep off the step 260.
Modification of the Embodiment
The present invention is described by the embodiment above, but the statements and drawings constituting a portion of this disclosure should not be construed as a limitation of the invention. Various alternate embodiments, examples, and operational techniques are apparent from this disclosure to a person skilled in the art.
(A) In the embodiment, the fuel-oil-tank facing face 220E has a fuel-oil-tank sloped face 220e, but no limitation is imposed thereby. The “sloped face” may be formed by the hydraulic-oil-tank facing face 210e or the fuel-oil-tank facing face 220E. For example, the hydraulic-oil-tank facing face 210e may have a hydraulic-oil-tank sloped face 210e2, as shown in FIG. 9. The fuel-oil-tank facing face 220E may have a fuel-oil-tank sloped face 220e, and the hydraulic-oil-tank facing face 210e may have a hydraulic-oil-tank sloped face 210e2, as shown in FIG. 10.
(B) In the embodiment, the fuel-oil-tank sloped face 220e communicates with the fuel oil tank upper face 220a and the fuel oil tank lower face 220b, but no limitation is imposed thereby. For example, the fuel-oil-tank sloped face 220e may communicate with the fuel oil tank upper face 220a and the fuel oil tank lower face 220b, as shown in FIG. 11. However, the upper end of the fuel-oil-tank sloped face 220e is preferably positioned higher than the hydraulic oil tank upper face 210a so that the breather hose 214 can be accommodated in the recessed section 221.
(C) In the embodiment, a vertical difference is formed between the placement face 260a and the fuel oil tank upper face 220a, but no limitation is imposed thereby. The placement face 260a and the fuel oil tank upper face 220a may be formed flush with each other, as shown in FIG. 12.
(D) In the embodiment, the fuel-oil-tank sloped face 220e is formed by a planar face, but no limitation is imposed thereby. The fuel-oil-tank sloped face 220e may be formed by a curved face, as shown in FIG. 13.
(E) In the embodiment, the hydraulic excavator 100 is a hydraulic excavator with a small rear swivel radius, but no limitation is imposed thereby.
(F) In the embodiment, the hydraulic excavator 100 comprises an exhaust gas treatment device 52, but may also comprise a muffler in place of the exhaust gas treatment device 52.
It is thus apparent that the present invention includes various embodiments and the like that are not described herein. Therefore, the technical range of the present invention is established only by the specific matters of the invention according to the claims reasonable from the description above.

## Claims

1. An oil storage tank comprising:
a hydraulic oil tank configured to store hydraulic oil;
a fuel oil tank configured to store fuel oil;
a breather valve disposed on the hydraulic oil tank; and
a breather hose connected to the breather valve,
the hydraulic oil tank including a first facing face facing the fuel oil tank,
the fuel oil tank including a second facing face facing the hydraulic oil tank,
the second facing face having a fuel-oil-tank adjacent face and a fuel-oil-tank sloped face, the fuel-oil-tank adjacent face extending along the hydraulic oil tank, and the fuel-oil-tank sloped face being connected to the fuel-oil-tank adjacent face and sloping relative to the fuel-oil-tank adjacent face so as to be away from the hydraulic oil tank, and
the breather hose being disposed along the fuel-oil-tank sloped face.

2. The oil storage tank according to claim 1, wherein
the fuel-oil-tank sloped face is connected to an upper face and a lower face of the fuel oil tank.

3. The oil storage tank according to claim 1, wherein
the breather hose has a first end portion coupled to the breather valve, and a second end portion disposed lower than the oil storage tank.

4. The oil storage tank according to claim 1, wherein
the first facing face has a hydraulic-oil-tank adjacent face and a hydraulic-oil-tank sloped face, the hydraulic-oil-tank adjacent face extending along the fuel oil tank, and the hydraulic-oil-tank sloped face being connected to the hydraulic-oil-tank adjacent face and sloping relative to the hydraulic-oil-tank adjacent face so as to be away from the fuel oil tank, and
the breather hose is disposed between the fuel-oil-tank sloped face and the hydraulic-oil-tank sloped face.

5. The oil storage tank according to claim 1, wherein
the hydraulic oil tank is disposed on a vehicle-body-interior side of the fuel oil tank.

6. An oil storage tank comprising:
a hydraulic oil tank configured to store hydraulic oil;
a fuel oil tank configured to store fuel oil;
a breather valve disposed on the hydraulic oil tank; and
a breather hose connected to the breather valve,
the hydraulic oil tank including a first facing face facing the fuel oil tank,
the fuel oil tank including a second facing face facing the hydraulic oil tank,
the first facing face having a hydraulic-oil-tank adjacent face and a hydraulic-oil-tank sloped face, the hydraulic-oil-tank adjacent face extending along the fuel oil tank, and the hydraulic-oil-tank sloped face being connected to the hydraulic-oil-tank adjacent face and sloping relative to the hydraulic-oil-tank adjacent face so as to be away from the fuel oil tank, and
the breather hose being disposed along the hydraulic-oil-tank sloped face.

7. A construction vehicle comprising:
the oil storage tank recited in claim 1;
a working unit configured to receive supply of the hydraulic oil from the hydraulic oil tank; and
an engine configured to receive supply of the fuel oil from the fuel oil tank.

8. The construction vehicle according to claim 7, further comprising
an exhaust gas treatment device configured to treat exhaust gas from the engine, the exhaust gas treatment device being disposed near the rear of the oil storage tank,
the fuel-oil-tank sloped face and the hydraulic-oil-tank sloped face being different from a face facing the exhaust gas treatment device.

9. The construction vehicle according to claim 7, wherein
a rear end of the hydraulic oil tank is positioned further forward than a rear end of the fuel oil tank in a longitudinal direction.

10. The construction vehicle according to claim 7, wherein
the oil storage tank includes a step member disposed above the hydraulic oil tank.

11. The construction vehicle according to claim 10, wherein
an upper face of the step member is lower than an upper face of the fuel oil tank in a vertical direction.

12. The construction vehicle according to claim 10, wherein
the hydraulic oil tank is disposed on a vehicle-body-interior side of the fuel oil tank.

13. A construction vehicle comprising:
the oil storage tank recited in claim 6;
a working unit configured to receive supply of the hydraulic oil from the hydraulic oil tank; and
an engine configured to receive supply of the fuel oil from the fuel oil tank.

14. The construction vehicle according to claim 13, further comprising
an exhaust gas treatment device configured to treat exhaust gas from the engine, the exhaust gas treatment device being disposed near the rear of the oil storage tank,
the fuel-oil-tank sloped face and the hydraulic-oil-tank sloped face being different from a face facing the exhaust gas treatment device.

15. The construction vehicle according to claim 13, wherein
a rear end of the hydraulic oil tank is positioned further forward than a rear end of the fuel oil tank in a longitudinal direction.

16. The construction vehicle according to claim 13, wherein
the oil storage tank includes a step member disposed above the hydraulic oil tank.

17. The construction vehicle according to claim 16, wherein
an upper face of the step member is lower than an upper face of the fuel oil tank in a vertical direction.

18. The construction vehicle according to claim 16, wherein
the hydraulic oil tank is disposed on a vehicle-body-interior side of the fuel oil tank.