Resin fuel tank and work machine

Abstract

The present invention provides a resin fuel tank and the like enabling the inside thereof to be cleaned easily. A resin fuel tank (10) mounted on a work machine is provided with: a main body section (11) for storing fuel; a bottom opening section (11e) provided in a bottom surface section (11a) of the main body section (11) and used for inserting a hand into an interior of the main body section (11); and a lid section (12) for closing the bottom opening section (11e).

Description

Plastic fuel tank and work machine

[0001] The present disclosure relates to a plastic fuel tank mounted on a work machine such as a construction machine, and the work machine.

[0002] In work machines such as construction machines, plastic fuel tanks are sometimes used as fuel tanks to store fuel supplied to the engine in order to reduce costs, enable a variety of shapes, reduce weight, and so on (see, for example, Patent Documents 1 and 2).

[0003] Japanese Patent Publication No. 2008-183967 Japanese Patent Publication No. 2002-339400

[0004] Depending on the quality of the stored fuel, sludge-like impurities such as sand and dirt contained in the fuel may accumulate inside the tank. The accumulated impurities must be removed because they can clog the passages that supply the fuel to the engine or cause engine malfunctions.

[0005] However, conventional plastic fuel tanks are not designed to allow for easy access to the inside for cleaning. As a result, it is necessary to turn the plastic fuel tank upside down after removing it from the work machine and drain impurities through the fuel filler opening at the top of the plastic fuel tank, making it difficult to clean the inside.

[0006] An object of one aspect of the present disclosure is to provide a plastic fuel tank or the like whose interior can be easily cleaned.

[0007] In order to solve the above problems, a plastic fuel tank according to one embodiment of the present disclosure is a plastic fuel tank mounted on a work machine, and includes a main body that stores fuel inside, a bottom opening provided on the bottom surface of the main body for inserting a hand into the inside, and a lid that closes the bottom opening.

[0008] According to one aspect of the present disclosure, it is possible to realize a resin fuel tank or the like whose interior can be easily cleaned.

[0009] 6 is a schematic perspective view showing the overall configuration of a work machine equipped with a fuel tank according to an embodiment of the present disclosure. FIG. 6 is a perspective view of the fuel tank according to an embodiment of the present disclosure, not including the lid. FIG. 7 is a perspective view showing the lower side of the fuel tank shown in FIG. 2 with the lid removed. FIG. 8 is a cross-sectional perspective view of a main part of the work machine where the fuel tank shown in FIG. 2 is installed. FIG. 9 is a perspective view of the upper part of the swivel bed, which is a main part of the work machine, viewed from the rear side of the swivel bed. FIG. 10 is a cross-sectional perspective view of a main part of the work machine where the fuel tank shown in FIG. 6 is installed. FIG. 11 is a cross-sectional view of a main part around the lid of the fuel tank shown in FIG. 6. FIG. 12 is a diagram showing the sealing function of fuel tank 10A shown in FIG. 6.

[0010] First Embodiment Hereinafter, one embodiment of the present disclosure will be described in detail.

[0011] 1 is a schematic perspective view showing the overall configuration of a work machine 1 equipped with a fuel tank according to an embodiment of the present disclosure. In this embodiment, a backhoe, which is a type of construction machine, is exemplified as the work machine 1.

[0012] As shown in Figure 1, the work machine 1 includes a traveling device 2, a swivel base 3, and a working device 4. The swivel base 3 is supported on the frame of the traveling device 2 via a bearing body so as to be rotatable about a vertical axis (an axis in the up-down direction). A cabin 5, an engine (prime mover) 6, a bonnet 7, a counterweight 8, a plastic fuel tank (plastic fuel tank) 10, etc. are mounted on the swivel base 3, and the working device 4 is provided.

[0013] The engine 6 is mounted on the rear of the swivel base 3 and is covered by a hood 7. A fuel tank 10 stores fuel to supply fuel to the engine 6 and is mounted on the rear of the swivel base 3 together with the engine 6. The fuel tank 10 is mounted on the rear of the swivel base 3 and on one side in the width direction of the swivel base 3, which is toward the left in the example of FIG. 1 . The counterweight 8 is a weight used to balance the weight of the working device 4 and is mounted on the swivel base 3 below the hood 7.

[0014] The working device 4 is a device that operates using hydraulic oil pressure as a working fluid pressure, and is installed at the front of the swivel base 3. The working device 4 includes a boom, arm, bucket, etc. that are rotated by a hydraulic cylinder, and performs work such as excavation and ground leveling.

[0015] (Fuel Tank) Fig. 2 is a perspective view of the fuel tank 10 excluding the lid 12. Fig. 3 is a perspective view showing the lower side of the fuel tank 10 with the lid 12 removed. The method for forming the fuel tank 10 is not particularly limited, but it may be formed by rotational molding, blow molding, injection molding, or the like, for example.

[0016] As shown in Figure 2, the fuel tank 10 has a main body 11 that stores fuel. The main body 11 has a complex outer shape with multiple projections and recesses on the side surfaces, but is generally rectangular box-shaped and has a bottom surface 11a, a top surface 11b, and side surfaces 11c. The side surfaces 11c are four side surfaces, front, rear, left, and right, but in this embodiment, there is no need to distinguish between them, so the four side surfaces are collectively referred to as side surfaces 11c.

[0017] The top surface 11b is provided with a supply port 11d. The supply port 11d is an opening for supplying fuel into the main body 11.

[0018] The bottom surface portion 11a is provided with a bottom opening 11e. The bottom opening 11e is an opening through which a hand can be inserted into the main body portion 11. The bottom opening 11e is formed to a size that allows an operator to insert their hand and wipe away impurities that have accumulated at the bottom of the interior using a cloth or the like. The bottom opening 11e is also an opening for discharging impurities that have accumulated at the bottom of the interior. As shown in FIG. 3 , the bottom opening 11e is configured to be able to be closed with a lid portion 12. In other words, the fuel tank 10 includes the lid portion 12 that closes the bottom opening 11e provided in the main body portion 11.

[0019] In the fuel tank 10 according to this embodiment, the main body 11 is provided with such a bottom opening 11e, so that impurities that have accumulated at the bottom of the interior of the main body 11 can be discharged through the bottom opening 11e without having to turn the fuel tank 10 upside down. Moreover, because a hand can be inserted into the interior through the bottom opening 11e, impurities adhering to the inner wall surface of the main body 11 can be easily wiped off with a cloth or the like. This makes it easy to clean the interior of the fuel tank 10 (main body 11).

[0020] The lid portion 12 may have any configuration as long as it can close the bottom opening 11e, but in this embodiment, the lid portion 12 is made of a plate-like member as will be described later.

[0021] 2 and 3, in this embodiment, the main body 11 has a protrusion 11f formed on the bottom surface 11a of the main body 11. The protrusion 11f has a hollow box shape that communicates with the interior of the main body 11, and a bottom opening 11e is formed in the bottom wall 11fa of the protrusion 11f.

[0022] In other words, the protrusion 11f is formed to protrude downward and continue from the bottom surface portion 11a, and the upper surface side of the protrusion 11f is open and communicates with the interior of the main body portion 11. In the examples of Figures 2 and 3, the protrusion 11f is shaped like a square box whose cross section when cut in the horizontal direction is square, but the cross section may be a box shape that is circular, elliptical, triangular, or polygonal. The protrusion 11f only needs to have a peripheral wall 11fb that continues from the bottom surface portion 11a of the main body portion 11 and a bottom wall 11fa that closes the lower end of the peripheral wall 11fb.

[0023] When a fuel tank is made of resin, the provision of an opening therein tends to cause deformation compared to a metal fuel tank. However, in the above-described configuration, the box-shaped protrusion 11f is provided, and the bottom opening 11fe is provided in the bottom wall 11fa of the protrusion 11f. Therefore, deformation due to the provision of the bottom opening 11fe can be suppressed. This provides resistance to deformation over time, and prevents the fuel inside from leaking through the gap between the bottom opening 11fe and the lid 12.

[0024] The main body 11 is also provided with a nozzle 14 for delivering fuel stored inside to the engine 6. As shown in FIG. 2, in a configuration in which the protrusion 11f is provided, the nozzle 14 is provided on the side of the wall 11fb of the protrusion 11f that is closer to the bottom surface 11a.

[0025] Impurities that get into the fuel tank 10 collect on the lowest protrusion 11f and accumulate around the bottom opening 11e, making it easy to remove them from the bottom opening 11e. Moreover, because the area where the impurities adhere is mostly the inner wall surface of the protrusion 11f, the area that needs to be wiped can be made small.

[0026] In this embodiment, for example, the bottom opening 11e is a circle with a diameter of 80 mm, the protrusion 11f has dimensions of 200 mm x 200 mm x 100 mm, and the thickness of the main body 11 is 6 mm.

[0027] 3, the lid 12 is a plate-like member that is pressed against the surface of the bottom opening 11e facing the lid 12 to close the bottom opening 11e. The lid 12 can be fixed to the main body 11 by screw fastening using bolts 17 and nuts 16. A drain hose 15 can be connected to the lid 12 to drain the fuel inside the main body 11.

[0028] Figure 4 is a cross-sectional perspective view of a main portion of the work machine 1 where the fuel tank 10 is installed. As shown in Figure 4, in the fuel tank 10 of this embodiment, nuts 16 for screwing the lid portion 12 with bolts 17 are embedded in the bottom wall 11fa of the protrusion 11f. This configuration makes it easy to attach and detach the lid portion 12 to and from the main body 11. In this embodiment, the nuts 16 are provided at the four corners of the bottom wall 11fa of the protrusion 11f, which is formed in a rectangular shape.

[0029] As shown in FIG. 4 , the lid 12 includes an O-ring (sealing member) 13 that seals the gap between the lid 12 and the bottom wall 11fa of the protrusion 11f. A groove is formed on the surface of the lid 12 facing the bottom wall 11fa at a position that surrounds the bottom opening 11e when the bottom opening 11e is closed, and the O-ring 13 is fitted into the groove. Alternatively, a groove may be formed around the bottom opening 11e in the bottom wall 11fa of the protrusion 11f, and the O-ring 13 may be fitted into the groove. The surfaces of the bottom wall 11fa and the lid 12 that contact the O-ring are preferably flat surfaces. The surfaces of the bottom wall 11fa and the lid 12 that contact the O-ring are raised to ensure a crushing margin for the O-ring, and these surfaces may be flat surfaces.

[0030] Although an O-ring is used as an example of the sealing member here, any sealing mechanism that seals the gap between the lid portion 12 and the bottom wall 11fa of the protrusion 11f may be used.

[0031] 4, the fuel tank 10 is fixed to the swivel base 3 with the bottom portion 11a placed on a frame 18 fixed to the swivel base 3. The fuel tank 10 is fixed using a band, a fixing bracket, or the like.

[0032] In this embodiment, the bottom surface 11a of the main body 11 and the frame 18 are parallel to the swivel base 3, but the bottom surface 11a may be formed with an inclined shape that narrows from the side surface 11c toward the protrusion 11f. In that case, the frame 18 is also formed with an inclined shape to support the inclined bottom surface 11a. By forming an inclination, impurities can be effectively guided to the protrusion 11f.

[0033] Figure 5 is a perspective view of the upper part of the swivel base 3, which is a main part of the work machine 1, as viewed from the back side of the swivel base 3. As shown in Figure 5, the swivel base 3 has an access opening 3a that passes through the swivel base 3 at a position opposite the bottom opening 11e of the fuel tank 10. The access opening 3a is an opening that allows a hand to reach the bottom opening 11e from the back side of the swivel base 3.

[0034] Since an access opening is provided in the swivel base, the inside of the plastic fuel tank can be cleaned by reaching through the access opening from the back side of the swivel base without removing the plastic fuel tank from the work machine.

[0035] The access opening 3 a may be sized to allow the lid 12 to be removed to the back side of the swivel base 3. With this configuration, the lid 12 removed from the main body 11 can be removed through the access opening 3 a to the back side of the swivel base 3, i.e., to the outside of the work machine 1. This makes it easy to clean the lid 12.

[0036] [Embodiment 2] Another embodiment of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0037] Fig. 6 is a perspective view of a fuel tank 10A according to another embodiment of the present disclosure. Fig. 7 is a perspective view showing the lower side of the fuel tank 10A with the lid 12A removed. Fig. 8 is a cross-sectional perspective view of a main portion of the work machine 1 where the fuel tank 10A is installed. Fig. 9 is a cross-sectional view of a main portion around the lid 12A of the fuel tank 10A. Fig. 10 is a diagram showing the sealing function of the fuel tank 10A.

[0038] The fuel tank 10 of embodiment 1 has a bottom opening 11fe provided in the bottom wall 11fa of the protrusion 11f formed on the bottom surface 11a of the main body 11, and the bottom opening 11e is closed by pressing a plate-shaped lid portion 12 against the surface surrounding the bottom opening 11e.

[0039] 6 to 8, in the fuel tank 10A of this embodiment, the main body 11 includes a metal opening member 20 integrally molded with the main body 11 at a bottom wall 11fa of a protrusion 11f formed on a bottom surface 11a of the main body 11. The opening member 20 has a cylindrical portion 20a and a first extension portion 20b extending radially outward from an upper end side of the cylindrical portion 20a, and the lower end side of the cylindrical portion 20a is a bottom opening 30c.

[0040] Specifically, the opening member 20 is integrally formed with the bottom wall 11fa by insert molding. The opening member 20 protrudes downward from the bottom wall 11fa. The first extension portion 20b is a plate-like member having an opening formed therein that corresponds to the inner diameter of the cylindrical portion 20a, and is connected to the cylindrical portion 20a by welding, for example. The inside of the cylindrical portion 20a communicates with the interior of the main body portion 11 via the opening formed in the first extension portion 20b.

[0041] 6 to 8 illustrate the first extending portion 20b having a rectangular shape that matches the shape of the bottom wall 11fa of the protrusion 11f, but the present invention is not limited to this. In this embodiment, nuts 16 for screwing the lid portion 12A with bolts 17 are embedded in the portion of the opening member 20 where the first extending portion 20b is located, more specifically, in the four corners of the rectangular shape.

[0042] The lid portion 12A has a bottomed tubular portion 21a that fits onto the outer periphery of the tubular portion 20a of the opening member 20 to close the bottom opening 20c. In this embodiment, the lid portion 12A has a second extension portion 21b that extends from the upper end side of the bottomed tubular portion 21a toward the radially outer side of the bottomed tubular portion 21a. The second extension portion 21b is a member for fixing the bottomed tubular portion 21a to the main body portion 11, and is formed in the same shape as the first extension portion 20b of the opening member 20. The lid portion 12A is screwed in place with the second extension portion 21b abutting against the first extension portion 20b of the opening member 20.

[0043] 9, the lid 12A is provided with an O-ring (sealing member) 13 on the inner peripheral surface of the bottomed cylindrical portion 21a, which seals the gap between the lid 12A and the cylindrical portion 20a of the opening member 20. A groove 21ab is formed on the inner peripheral surface 21aa of the bottomed cylindrical portion 21a of the lid 12A, and the O-ring 13 is fitted into the groove 21ab. A groove may also be formed on the outer peripheral surface of the cylindrical portion 20a of the opening member 20, and the O-ring 13 may be fitted into the groove.

[0044] Here, an O-ring is exemplified as the sealing member, but any sealing mechanism that seals the gap between the cylindrical portion 20a of the opening member 20 and the bottomed cylindrical portion 2a may be used.

[0045] As shown in Figure 10, fuel 23 that has seeped into the gap C between the bottomed cylindrical portion 21a of the lid portion 12A and the lower end of the cylindrical portion 20a of the opening member 20 and between the bottomed cylindrical portion 21a and the cylindrical portion 20a is prevented from further seeping in by the O-ring 13.

[0046] In this embodiment, the main body 11 is provided with a protrusion 11f and the opening member 20 is provided on the bottom wall 11fa thereof, but the opening member 20 may be provided on the bottom surface 11a of the main body 11 without providing the protrusion 11f.

[0047] Although the present embodiment illustrates a configuration in which one O-ring 13 is provided, multiple O-rings 13 may be provided to prevent fuel leakage at multiple stages. An additional O-ring (sealing member) may be provided between the first extension 20b on the main body 11 side and the second extension 21b on the lid 12A side, which come into contact when the lid 12A is fixed to the main body 11.

[0048] (Summary) The plastic fuel tank in aspect 1 of the present disclosure is a plastic fuel tank mounted on a work machine, and includes a main body that stores fuel inside, a bottom opening provided on the bottom surface of the main body for inserting a hand into the inside, and a lid that closes the bottom opening.

[0049] With the above-mentioned configuration, impurities accumulated inside the plastic fuel tank can be drained through the bottom opening without turning the tank upside down. Moreover, since the bottom opening allows a hand to be inserted inside the tank, impurities adhering to the inner wall surface can be easily wiped off with a cloth or the like, making it easy to clean the inside.

[0050] In a plastic fuel tank in aspect 2 of the present disclosure, in the above-described aspect 1, the main body may have a protrusion formed on the bottom surface, the protrusion having a hollow box shape that communicates with the interior, and the bottom opening may be formed on the bottom surface of the protrusion.

[0051] Although plastic fuel tanks are more susceptible to deformation when an opening is provided than a metal fuel tank, the above-described configuration provides a box-shaped protrusion with a bottom opening on the bottom surface of the protrusion, thereby suppressing deformation caused by the bottom opening. This provides resistance to deformation over time and prevents fuel from leaking from the gap between the bottom opening and the lid.

[0052] The plastic fuel tank of Aspect 3 of the present disclosure is the one of Aspects 1 or 2, which has a flat surface on at least a portion of the surface surrounding the bottom opening that faces the lid, and the lid is a plate-like member that is pressed against the flat surface to close the bottom opening, and a seal member is provided between the flat surface and the lid. The flat surface around the bottom opening and the lid made of a plate-like member can be easily wiped off even if impurities or fuel adhere to them.

[0053] In a fourth aspect of the present disclosure, the plastic fuel tank of the third aspect may have a nut for screwing the lid into a surface of the periphery of the bottom opening facing the lid. With this configuration, the lid can be easily and securely attached to the main body.

[0054] In aspect 5 of the present disclosure, the plastic fuel tank is configured as in aspect 1 or 2, wherein the main body portion is provided with a metal opening member integrally molded with the main body portion on the bottom surface portion or the bottom surface of the protrusion, the opening member having a cylindrical portion and a first extension portion extending radially outward from the upper end side of the cylindrical portion, the lower end side of the cylindrical portion being the bottom opening, the lid portion having a bottomed cylindrical portion that is fitted onto the outer periphery of the cylindrical portion to close the bottom opening, and a sealing member may be provided between the cylindrical portion and the bottomed cylindrical portion.

[0055] A plastic fuel tank in aspect 6 of the present disclosure is similar to aspect 5 in that the lid portion has a second extension portion extending from the upper end side of the bottomed tubular portion toward the radially outer side of the bottomed tubular portion, and the lid portion may be screwed in place with the second extension portion abutting against the first extension portion.

[0056] A seventh aspect of the present disclosure provides a plastic fuel tank according to the sixth aspect, wherein a nut for screwing the lid portion is embedded in a portion where the first extension portion is located.

[0057] The work machine in aspect 8 of the present disclosure comprises a swivel base, a prime mover mounted on the swivel base, a work device provided on the swivel base, and a plastic fuel tank described in any of aspects 1 to 7 that is mounted on the swivel base and contains fuel to be supplied to the prime mover, and the swivel base has an access opening that passes through the swivel base at a position opposite the opening of the plastic fuel tank, allowing the bottom opening to be reached from the back side of the swivel base.

[0058] According to the above configuration, the inside of the plastic fuel tank can be cleaned by reaching in through the access opening from the rear side of the swivel base without removing the plastic fuel tank from the work machine.

[0059] In a work machine according to a ninth aspect of the present disclosure, in accordance with the eighth aspect, the access opening may be of a size that allows the lid to be removed to the underside of the swivel base. In the above configuration, the lid removed from the main body can be removed to the outside of the work machine through the access opening, making it easy to clean the lid.

[0060] [Additional Notes] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure.

[0061] REFERENCE SIGNS LIST 1 Work machine 2 Traveling device 3 Swivel base 3a Access opening 4 Work device 6 Engine (prime mover) 10 Fuel tank (plastic fuel tank) 11 Main body 11a Bottom surface 11e Bottom opening 11f Protrusion 11fa Bottom wall 11fb Peripheral wall 12, 12A Lid 16 Nut 18 Frame 20 Opening member 20a Cylindrical portion 20b First extension 20c Bottom opening 21a Bottomed cylindrical portion 21b Second extension

Claims

1. A plastic fuel tank mounted on a work machine, comprising: a main body that stores fuel inside; a bottom opening provided on the bottom surface of the main body for inserting a hand into the inside; and a lid that closes the bottom opening.

2. A plastic fuel tank as set forth in claim 1, wherein the main body has a protrusion formed on the bottom surface, the protrusion having a hollow box shape that communicates with the interior, and the bottom opening is formed on the bottom surface of the protrusion.

3. A plastic fuel tank as set forth in claim 1 or 2, wherein the bottom opening has a flat surface on at least a portion of the surface facing the lid, the lid is a plate-like member that is pressed against the flat surface to close the bottom opening, and a sealing member is provided between the flat surface and the lid.

4. A plastic fuel tank as set forth in claim 3, wherein nuts for screwing the lid are embedded in the surface of the periphery of the bottom opening on the side facing the lid.

5. A plastic fuel tank as set forth in claim 1 or 2, wherein the main body comprises a metal opening member integrally molded with the main body on the bottom surface or the bottom surface of the protrusion, the opening member having a cylindrical portion and a first extension portion extending radially outward from the upper end side of the cylindrical portion, the lower end side of the cylindrical portion being the bottom opening, the lid portion having a bottomed cylindrical portion that fits onto the outer periphery of the cylindrical portion to close the bottom opening, and a sealing member is provided between the cylindrical portion and the bottomed cylindrical portion.

6. A plastic fuel tank as set forth in claim 5, wherein the lid has a second extension extending from the upper end side of the bottomed tubular portion toward the radially outer side of the bottomed tubular portion, and the lid is fastened with screws with the second extension abutting against the first extension.

7. A plastic fuel tank as set forth in claim 6, wherein a nut for screwing the lid is embedded in the portion where the first extension is located.

8. A work machine comprising: a swivel base; a prime mover mounted on the swivel base; a work device provided on the swivel base; and a plastic fuel tank as described in claim 1 or 2 mounted on the swivel base and containing fuel to be supplied to the prime mover, wherein the swivel base has an access opening that passes through the swivel base at a position opposite the bottom opening of the plastic fuel tank, allowing a hand to reach the bottom opening from the back side of the swivel base.

9. A work machine according to claim 8, wherein the access opening is sized to allow the cover to be removed to the rear side of the swivel base.

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